Interference reduction between RF communications bands

ABSTRACT

Radio frequency (RF) power amplifier (PA) circuitry and a PA envelope power supply are disclosed. The RF PA circuitry receives and amplifies an RF input signal to provide an RF output signal using an envelope power supply signal, which is provided by the PA envelope power supply. The RF PA circuitry operates in either a normal RF spectral emissions mode or a reduced RF spectral emissions mode. When reduced RF spectral emissions are required, the RF PA circuitry operates in the reduced RF spectral emissions mode. As such, at a given RF output power, during the reduced RF spectral emissions mode, RF spectral emissions of the RF output signal are less than during the normal RF spectral emissions mode. As a result, the reduced RF spectral emissions mode may be used to reduce interference between RF communications bands.

PRIORITY CLAIMS

The present application claims priority to U.S. provisional patentapplication No. 61/489,487, filed May 24, 2011.

The present application claims priority to and is a continuation-in-partof U.S. patent application Ser. No. 13/090,663, filed Apr. 20, 2011,entitled “QUADRATURE POWER AMPLIFIER ARCHITECTURE,” now U.S. Pat. No.8,538,355, which claims priority to U.S. Provisional Patent ApplicationNo. 61/325,859, filed Apr. 20, 2010; No. 61/359,487, filed Jun. 29,2010; No. 61/370,554, filed Aug. 4, 2010; No. 61/380,522, filed Sep. 7,2010; No. 61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov.29, 2010.

The present application claims priority to and is a continuation-in-partof U.S. Patent Application No. 13/172,371, filed Jun. 29, 2011, entitled“AUTOMATICALLY CONFIGURABLE 2-WIRE/3-WIRE SERIAL COMMUNICATIONSINTERFACE,” now U.S. Pat. No. 8,983,409, which claims priority to U.S.Provisional Patent Applications No. 61/359,487, filed Jun. 29, 2010; No.61/370,554, tiled Aug. 4, 2010; No. 61/380,522, filed Sep. 7, 2010; No.61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010.U.S. patent application Ser. No. 13/172,371 is a continuation-in-part ofU.S. patent application Ser. No. 13/090,663, filed Apr. 20, 2011, whichclaims priority to U.S. Provisional Patent Applications No. 61/325,859,filed Apr. 20, 2010; No. 61/359,487, filed Jun. 29, 2010; No.61/370,554, filed Aug. 4, 2010; No. 61/380,522, filed Sep. 7. 2010; No.61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010.

The present application claims priority to and is a continuation-in-partof U.S. patent application Ser. No. 13/198,074, filed Aug. 4, 2011,entitled “FREQUENCY CORRECTION OF A PROGRAMMABLE FREQUENCY OSCILLATOR BYPROPAGATION DELAY COMPENSATION,” now U.S. Pat. No. 8,515,361, whichclaims priority to U.S. Provisional Patent Applications No. 61/370,554filed Aug. 4, 2010; No. 61/380,522, filed Sep. 7, 2010; No. 61/410,071,filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010. U.S. patentapplication Ser. No. 13/198,074 is a continuation-in-part of U.S. patentapplication Ser. No. 13/090,663, filed Apr. 20, 2011, which claimspriority to U.S. Provisional Patent Applications No. 61/325,859, filedApr. 20, 2010; No. 61/359,487, filed Jun. 29, 2010; No. 61/370,554,filed Aug. 4, 2010; Ser. No. 61/380,522, filed Sep. 7, 2010; No.61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010.U.S. patent application Ser. No. 13/198,074 is also acontinuation-in-part of U.S. patent application Ser. No. 13/172,371,filed Jun. 29, 2011, which claims priority to U.S. Provisional PatentApplications No. 61/359,487, filed Jun. 29, 2010; No. 61/370,554, filedAug. 4, 2010; No. 61/380,522, filed Sep. 7, 2010; No. 61/410,071, filedNov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010.

The present application claims priority to and is a continuation-in-partof U.S. patent application Ser. No. 13/226,831, filed Sep. 7, 2011,entitled “VOLTAGE COMPATIBLE CHARGE PUMP BUCK AND BUCK POWER SUPPLIES,”which claims priority to U.S. Provisional Patent Application No.61/380,522, filed Sep. 7, 2010; No. 61/410,071, filed Nov. 4, 2010; andNo. 61/417,633, filed Nov. 29, 2010. U.S. patent application Ser. No.13/226,831 is a continuation-in-part of U.S. patent application Ser. No.13/090,663, filed Apr. 20, 2011, which claims priority to U.S.Provisional Patent Application No. 61/325,859, filed Apr. 20, 2010; No.61/359,487, filed Jun. 29, 2010; No. 61/370,554, filed Aug. 4, 2010; No.61/380,522, filed Sep. 7, 2010; No. 61/410,071, filed Nov. 4, 2010; andNo. 61/417,633, filed Nov. 29, 2010. U.S. patent application Ser. No.13/226,831 is also a continuation-in-part of U.S. patent applicationSer. No. 13/172,371, filed Jun. 29, 2011, which claims priority to U.S.Provisional Patent Application No. 61/359,487, filed Jun. 29, 2010; No.61/370,554, filed Aug. 4, 2010; No. 61/380,522, filed Sep. 7, 2010; No.61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010.In addition, U.S. patent application Ser. No. 13/226,831 is acontinuation-in-part of U.S. patent application Ser. No. 13/198,074,filed Aug. 4, 2011, which claims priority to U.S. Provisional PatentApplication No. 61/370,554, filed Aug. 4, 2010; No. 61/380,522, filedSep. 7, 2010; No. 61/410,071, filed Nov. 4, 2010; and No. 61/417,633,filed Nov. 29, 2010.

All of the applications listed above are hereby incorporated herein byreference in their entireties.

FIELD OF THE DISCLOSURE

Embodiments of the present disclosure relate to radio frequency (RF)power amplifier (PA) circuitry, which may be used in RF communicationssystems.

BACKGROUND OF THE DISCLOSURE

As wireless communications technologies evolve, wireless communicationssystems become increasingly sophisticated. As such, wirelesscommunications protocols continue to expand and change to take advantageof the technological evolution. As a result, to maximize flexibility,many wireless communications devices must be capable of supporting anynumber of wireless communications protocols, including protocols thatoperate using different communications modes, such as a half-duplex modeor a full-duplex mode, and including protocols that operate usingdifferent frequency bands. Further, the different communications modesmay include different types of RF modulation modes, each of which mayhave certain performance requirements, such as specific out-of-bandemissions requirements or symbol differentiation requirements. In thisregard, certain requirements may mandate operation in a linear mode.Other requirements may be less stringent that may allow operation in anon-linear mode to increase efficiency. Wireless communications devicesthat support such wireless communications protocols may be referred toas multi-mode multi-band communications devices. The linear mode relatesto RF signals that include amplitude modulation (AM). The non-linearmode relates to RF signals that do not include AM. Since non-linear modeRF signals do not include AM, devices that amplify such signals may beallowed to operate in saturation. Devices that amplify linear mode RFsignals may operate with some level of saturation, but must be able toretain AM characteristics sufficient for proper operation.

A half-duplex mode is a two-way mode of operation, in which a firsttransceiver communicates with a second transceiver; however, only onetransceiver transmits at a time. Therefore, the transmitter and receiverin such a transceiver do not operate simultaneously. For example,certain telemetry systems operate in a send-then-wait-for-reply manner.Many time division duplex (TDD) systems, such as certain Global Systemfor Mobile communications (GSM) systems, operate using the half-duplexmode. A full-duplex mode is a simultaneous two-way mode of operation, inwhich a first transceiver communicates with a second transceiver, andboth transceivers may transmit simultaneously. Therefore, thetransmitter and receiver in such a transceiver must be capable ofoperating simultaneously. In a full-duplex transceiver, signals from thetransmitter should not overly interfere with signals received by thereceiver; therefore, transmitted signals are at transmit frequenciesthat are different from received signals, which are at receivefrequencies. Many frequency division duplex (FDD) systems, such ascertain wideband code division multiple access (WCDMA) systems orcertain long term evolution (LTE) systems, operate using a full-duplexmode.

As a result of the differences between full duplex operation and halfduplex operation, RF front-end circuitry may need specific circuitry foreach mode. Additionally, support of multiple frequency bands may requirespecific circuitry for each frequency band or for certain groupings offrequency bands. FIG. 1 shows a traditional multi-mode multi-bandcommunications device 10 according to the prior art. The traditionalmulti-mode multi-band communications device 10 includes a traditionalmulti-mode multi-band transceiver 12, traditional multi-mode multi-bandPA circuitry 14, traditional multi-mode multi-band front-end aggregationcircuitry 16, and an antenna 18. The traditional multi-mode multi-bandPA circuitry 14 includes a first traditional PA 20, a second traditionalPA 22, and up to and including an N^(TH) traditional PA 24.

The traditional multi-mode multi-band transceiver 12 may select one ofmultiple communications modes, which may include a half-duplex transmitmode, a half-duplex receive mode, a full-duplex mode, a linear mode, anon-linear mode, multiple RF modulation modes, or any combinationthereof. Further, the traditional multi-mode multi-band transceiver 12may select one of multiple frequency bands. The traditional multi-modemulti-band transceiver 12 provides an aggregation control signal ACS tothe traditional multi-mode multi-band front-end aggregation circuitry 16based on the selected mode and the selected frequency band. Thetraditional multi-mode multi-band front-end aggregation circuitry 16 mayinclude various RF components, including RF switches; RF filters, suchas bandpass filters, harmonic filters, and duplexers; RF amplifiers,such as low noise amplifiers (LNAs); impedance matching circuitry; thelike; or any combination thereof. In this regard, routing of RF receivesignals and RF transmit signals through the RF components may be basedon the selected mode and the selected frequency band as directed by theaggregation control signal ACS.

The first traditional PA 20 may receive and amplify a first traditionalRF transmit signal FTTX from the traditional multi-mode multi-bandtransceiver 12 to provide a first traditional amplified RF transmitsignal FTATX to the antenna 18 via the traditional multi-mode multi-bandfront-end aggregation circuitry 16. The second traditional PA 22 mayreceive and amplify a second traditional RF transmit signal STTX fromthe traditional multi-mode multi-band transceiver 12 to provide a secondtraditional RF amplified transmit signal STATX to the antenna 18 via thetraditional multi-mode multi-band front-end aggregation circuitry 16.The N^(TH) traditional PA 24 may receive an amplify an N^(TH)traditional RF transmit signal NTTX from the traditional multi-modemulti-band transceiver 12 to provide an N^(TH) traditional RF amplifiedtransmit signal NTATX to the antenna 18 via the traditional multi-modemulti-band front-end aggregation circuitry 16.

The traditional multi-mode multi-band transceiver 12 may receive a firstRF receive signal FRX, a second RF receive signal SRX, and up to andincluding an M^(TH) RF receive signal MRX from the antenna 18 via thetraditional multi-mode multi-band front-end aggregation circuitry 16.Each of the RF receive signals FRX, SRX, MRX may be associated with atleast one selected mode, at least one selected frequency band, or both.Similarly, each of the traditional RF transmit signals FTTX, STTX, NTTXand corresponding traditional amplified RF transmit signals FTATX,STATX, NTATX may be associated with at least one selected mode, at leastone selected frequency band, or both.

Portable wireless communications devices are typically battery powered,need to be relatively small, and have low cost. As such, to minimizesize, cost, and power consumption, multi-mode multi-band RF circuitry insuch a device needs to be as simple, small, and efficient as ispractical. Thus, there is a need for multi-mode multi-band RF circuitryin a multi-mode multi-band communications device that is low cost,small, simple, efficient, and meets performance requirements.

SUMMARY OF THE EMBODIMENTS

Embodiments of the present disclosure relate to RF PA circuitry and a PAenvelope power supply. The RF PA circuitry receives and amplifies an RFinput signal to provide an RF output signal using an envelope powersupply signal, which is provided by the PA envelope power supply. The RFPA circuitry operates in either a normal RF spectral emissions mode or areduced RF spectral emissions mode. When reduced RF spectral emissionsare required, the RF PA circuitry operates in the reduced RF spectralemissions mode. As such, at a given RF output power, during the reducedRF spectral emissions mode, RF spectral emissions of the RF outputsignal are less than during the normal RF spectral emissions mode. As aresult, the reduced RF spectral emissions mode may be used to reduceinterference between RF communications bands.

Those skilled in the art will appreciate the scope of the presentdisclosure and realize additional aspects thereof after reading thefollowing detailed description of the preferred embodiments inassociation with the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The accompanying drawing figures incorporated in and forming a part ofthis specification illustrate several aspects of the disclosure, andtogether with the description serve to explain the principles of thedisclosure.

FIG. 1 shows a traditional multi-mode multi-band communications deviceaccording to the prior art.

FIG. 2 shows an RF communications system according to one embodiment ofthe RF communications system.

FIG. 3 shows the RF communications system according to an alternateembodiment of the RF communications system.

FIG. 4 shows the RF communications system according to an additionalembodiment of the RF communications system.

FIG. 5 shows the RF communications system according to anotherembodiment of the RF communications system.

FIG. 6 shows the RF communications system according to a furtherembodiment of the RF communications system.

FIG. 7 shows the RF communications system according to one embodiment ofthe RF communications system.

FIG. 8 shows details of RF power amplifier (PA) circuitry illustrated inFIG. 5 according to one embodiment of the RF PA circuitry.

FIG. 9 shows details of the RF PA circuitry illustrated in FIG. 5according to an alternate embodiment of the RF PA circuitry.

FIG. 10 shows the RF communications system according to one embodimentof the RF communications system.

FIG. 11 shows the RF communications system according to an alternateembodiment of the RF communications system.

FIG. 12 shows details of a direct current (DC)-DC converter illustratedin FIG. 11 according to an alternate embodiment of the DC-DC converter.

FIG. 13 shows details of the RF PA circuitry illustrated in FIG. 5according to one embodiment of the RF PA circuitry.

FIG. 14 shows details of the RF PA circuitry illustrated in FIG. 6according to an alternate embodiment of the RF PA circuitry.

FIG. 15 shows details of a first RF PA and a second RF PA illustrated inFIG. 14 according to one embodiment of the first RF PA and the second RFPA.

FIG. 16 shows details of a first non-quadrature PA path and a secondnon-quadrature PA path illustrated in FIG. 15 according to oneembodiment of the first non-quadrature PA path and the secondnon-quadrature PA path.

FIG. 17 shows details of a first quadrature PA path and a secondquadrature PA path illustrated in FIG. 15 according to one embodiment ofthe first quadrature PA path and the second quadrature PA path.

FIG. 18 shows details of a first in-phase amplification path, a firstquadrature-phase amplification path, a second in-phase amplificationpath, and a second quadrature-phase amplification path illustrated inFIG. 17 according to one embodiment of the first in-phase amplificationpath, the first quadrature-phase amplification path, the second in-phaseamplification path, and the second quadrature-phase amplification path.

FIG. 19 shows details of the first quadrature PA path and the secondquadrature PA path illustrated in FIG. 15 according to an alternateembodiment of the first quadrature PA path and the second quadrature PApath.

FIG. 20 shows details of the first in-phase amplification path, thefirst quadrature-phase amplification path, the second in-phaseamplification path, and the second quadrature-phase amplification pathillustrated in FIG. 19 according to an alternate embodiment of the firstin-phase amplification path, the first quadrature-phase amplificationpath, the second in-phase amplification path, and the secondquadrature-phase amplification path.

FIG. 21 shows details of the first RF PA and the second RF PAillustrated in FIG. 14 according an alternate embodiment of the first RFPA and the second RF PA.

FIG. 22 shows details of the first non-quadrature PA path, the firstquadrature PA path, and the second quadrature PA path illustrated inFIG. 21 according to an additional embodiment of the firstnon-quadrature PA path, the first quadrature PA path, and the secondquadrature PA path.

FIG. 23 shows details of a first feeder PA stage and a first quadratureRF splitter illustrated in FIG. 16 and FIG. 17, respectively, accordingto one embodiment of the first feeder PA stage and the first quadratureRF splitter.

FIG. 24 shows details of the first feeder PA stage and the firstquadrature RF splitter illustrated in FIG. 16 and FIG. 17, respectively,according to an alternate embodiment of the first feeder PA stage andthe first quadrature RF splitter.

FIG. 25 is a graph illustrating output characteristics of a first outputtransistor element illustrated in FIG. 24 according to one embodiment ofthe first output transistor element.

FIG. 26 illustrates a process for matching an input impedance to aquadrature RF splitter to a target load line of a feeder PA stage.

FIG. 27 shows details of the first RF PA illustrated in FIG. 14according an alternate embodiment of the first RF PA.

FIG. 28 shows details of the second RF PA illustrated in FIG. 14according an alternate embodiment of the second RF PA.

FIG. 29 shows details of a first in-phase amplification path, a firstquadrature-phase amplification path, and a first quadrature RF combinerillustrated in FIG. 22 according to one embodiment of the first in-phaseamplification path, the first quadrature-phase amplification path, andthe first quadrature RF combiner.

FIG. 30 shows details of a first feeder PA stage, a first quadrature RFsplitter, a first in-phase final PA impedance matching circuit, a firstin-phase final PA stage, a first quadrature-phase final PA impedancematching circuit, and a first quadrature-phase final PA stageillustrated in FIG. 29 according to one embodiment of the first feederPA stage, the first quadrature RF splitter, the first in-phase final PAimpedance matching circuit, the first in-phase final PA stage, the firstquadrature-phase final PA impedance matching circuit, and the firstquadrature-phase final PA stage.

FIG. 31 shows details of the first feeder PA stage, the first quadratureRF splitter, the first in-phase final PA impedance matching circuit, thefirst in-phase final PA stage, the first quadrature-phase final PAimpedance matching circuit, and the first quadrature-phase final PAstage illustrated in FIG. 29 according to an alternate embodiment of thefirst feeder PA stage, the first quadrature RF splitter, the firstin-phase final PA impedance matching circuit, the first in-phase finalPA stage, the first quadrature-phase final PA impedance matchingcircuit, and the first quadrature-phase final PA stage.

FIG. 32 shows details of first phase-shifting circuitry and a firstWilkinson RF combiner illustrated in FIG. 29 according to one embodimentof the first phase-shifting circuitry and the first Wilkinson RFcombiner.

FIG. 33 shows details of the second non-quadrature PA path illustratedin FIG. 16 and details of the second quadrature PA path illustrated inFIG. 18 according to one embodiment of the second non-quadrature PA pathand the second quadrature PA path.

FIG. 34 shows details of a second feeder PA stage, a second quadratureRF splitter, a second in-phase final PA impedance matching circuit, asecond in-phase final PA stage, a second quadrature-phase final PAimpedance matching circuit, and a second quadrature-phase final PA stageillustrated in FIG. 33 according to one embodiment of the second feederPA stage, the second quadrature RF splitter, the second in-phase finalPA impedance matching circuit, the second in-phase final PA stage, thesecond quadrature-phase final PA impedance matching circuit, and thesecond quadrature-phase final PA stage.

FIG. 35 shows details of second phase-shifting circuitry and a secondWilkinson RF combiner illustrated in FIG. 33 according to one embodimentof the second phase-shifting circuitry and the second Wilkinson RFcombiner.

FIG. 36 shows details of a first PA semiconductor die illustrated inFIG. 30 according to one embodiment of the first PA semiconductor die.

FIG. 37 shows details of the RF PA circuitry illustrated in FIG. 5according to one embodiment of the RF PA circuitry.

FIG. 38 shows details of the RF PA circuitry illustrated in FIG. 5according to an alternate embodiment of the RF PA circuitry.

FIG. 39 shows details of the RF PA circuitry illustrated in FIG. 5according to an additional embodiment of the RF PA circuitry.

FIG. 40 shows details of the first RF PA, the second RF PA, and PA biascircuitry illustrated in FIG. 13 according to one embodiment of thefirst RF PA, the second RF PA, and the PA bias circuitry.

FIG. 41 shows details of driver stage current digital-to-analogconverter (IDAC) circuitry and final stage IDAC circuitry illustrated inFIG. 40 according to one embodiment of the driver stage IDAC circuitryand the final stage IDAC circuitry.

FIG. 42 shows details of driver stage current reference circuitry andfinal stage current reference circuitry illustrated in FIG. 41 accordingto one embodiment of the driver stage current reference circuitry andthe final stage current reference circuitry.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The embodiments set forth below represent the necessary information toenable those skilled in the art to practice the disclosure andillustrate the best mode of practicing the disclosure. Upon reading thefollowing description in light of the accompanying drawing figures,those skilled in the art will understand the concepts of the disclosureand will recognize applications of these concepts not particularlyaddressed herein. It should be understood that these concepts andapplications fall within the scope of the disclosure and theaccompanying claims.

FIG. 2 shows an RF communications system 26 according to one embodimentof the RF communications system 26. The RF communications system 26includes RF modulation and control circuitry 28, RF PA circuitry 30, anda DC-DC converter 32. The RF modulation and control circuitry 28provides an envelope control signal ECS to the DC-DC converter 32 andprovides an RF input signal RFI to the RF PA circuitry 30. The DC-DCconverter 32 provides a bias power supply signal BPS and an envelopepower supply signal EPS to the RF PA circuitry 30. The envelope powersupply signal EPS may be based on the envelope control signal ECS. Assuch, a magnitude of the envelope power supply signal EPS may becontrolled by the RF modulation and control circuitry 28 via theenvelope control signal ECS. The RF PA circuitry 30 may receive andamplify the RF input signal RFI to provide an RF output signal RFO. Theenvelope power supply signal EPS may provide power for amplification ofthe RF input signal RFI to the RF PA circuitry 30. The RF PA circuitry30 may use the bias power supply signal BPS to provide biasing ofamplifying elements in the RF PA circuitry 30.

In a first embodiment of the RF communications system 26, the RFcommunications system 26 is a multi-mode RF communications system 26. Assuch, the RF communications system 26 may operate using multiplecommunications modes. In this regard, the RF modulation and controlcircuitry 28 may be multi-mode RF modulation and control circuitry 28and the RF PA circuitry 30 may be multi-mode RF PA circuitry 30. In asecond embodiment of the RF communications system 26, the RFcommunications system 26 is a multi-band RF communications system 26. Assuch, the RF communications system 26 may operate using multiple RFcommunications bands. In this regard, the RF modulation and controlcircuitry 28 may be multi-band RF modulation and control circuitry 28and the RF PA circuitry 30 may be multi-band RF PA circuitry 30. In athird embodiment of the RF communications system 26, the RFcommunications system 26 is a multi-mode multi-band RF communicationssystem 26. As such, the RF communications system 26 may operate usingmultiple communications modes, multiple RF communications bands, orboth. In this regard, the RF modulation and control circuitry 28 may bemulti-mode multi-band RF modulation and control circuitry 28 and the RFPA circuitry 30 may be multi-mode multi-band RF PA circuitry 30.

The communications modes may be associated with any number of differentcommunications protocols, such as Global System of Mobile communications(GSM), Gaussian Minimum Shift Keying (GMSK), IS-136, Enhanced Data ratesfor GSM Evolution (EDGE), Code Division Multiple Access (CDMA),Universal Mobile Telecommunications System (UMTS) protocols, such asWideband CDMA (WCDMA), Worldwide Interoperability for Microwave Access(WIMAX), Long Term Evolution (LTE), or the like. The GSM, GMSK, andIS-136 protocols typically do not include amplitude modulation (AM). Assuch, the GSM, GMSK, and IS-136 protocols may be associated with anon-linear mode. Further, the GSM, GMSK, and IS-136 protocols may beassociated with a saturated mode. The EDGE, CDMA, UMTS, WCDMA, WIMAX,and LTE protocols may include AM. As such, the EDGE, CDMA, UMTS, WCDMA,WIMAX, and LTE protocols may be associated with a linear mode.

In one embodiment of the RF communications system 26, the RFcommunications system 26 is a mobile communications terminal, such as acell phone, smartphone, laptop computer, tablet computer, personaldigital assistant (PDA), or the like. In an alternate embodiment of theRF communications system 26, the RF communications system 26 is a fixedcommunications terminal, such as a base station, a cellular basestation, a wireless router, a hotspot distribution node, a wirelessaccess point, or the like. The antenna 18 may include any apparatus forconveying RF transmit and RF receive signals to and from at least oneother RF communications system. As such, in one embodiment of theantenna 18, the antenna 18 is a single antenna. In an alternateembodiment of the antenna 18, the antenna 18 is an antenna array havingmultiple radiating and receiving elements. In an additional embodimentof the antenna 18, the antenna 18 is a distribution system fortransmitting and receiving RF signals.

FIG. 3 shows the RF communications system 26 according to an alternateembodiment of the RF communications system 26. The RF communicationssystem 26 illustrated in FIG. 3 is similar to the RF communicationssystem 26 illustrated in FIG. 2, except in the RF communications system26 illustrated in FIG. 3, the RF modulation and control circuitry 28provides a first RF input signal FRFI, a second RF input signal SRFI,and a PA configuration control signal PCC to the RF PA circuitry 30. TheRF PA circuitry 30 may receive and amplify the first RF input signalFRFI to provide a first RF output signal FRFO. The envelope power supplysignal EPS may provide power for amplification of the first RF inputsignal FRFI to the RF PA circuitry 30. The RF PA circuitry 30 mayreceive and amplify the second RF input signal SRFI to provide a secondRF output signal SRFO. The envelope power supply signal EPS may providepower for amplification of the second RF output signal SRFO to the RF PAcircuitry 30. Certain configurations of the RF PA circuitry 30 may bebased on the PA configuration control signal PCC. As a result, the RFmodulation and control circuitry 28 may control such configurations ofthe RF PA circuitry 30.

FIG. 4 shows the RF communications system 26 according to an additionalembodiment of the RF communications system 26. The RF communicationssystem 26 illustrated in FIG. 4 is similar to the RF communicationssystem 26 illustrated in FIG. 3, except in the RF communications system26 illustrated in FIG. 4, the RF PA circuitry 30 does not provide thefirst RF output signal FRFO and the second RF output signal SRFO.Instead, the RF PA circuitry 30 may provide one of a first alpha RFtransmit signal FATX, a second alpha RF transmit signal SATX, and up toand including a P^(TH) alpha RF transmit signal PATX based on receivingand amplifying the first RF input signal FRFI. Similarly, the RF PAcircuitry 30 may provide one of a first beta RF transmit signal FBTX, asecond beta RF transmit signal SBTX, and up to and including a Q^(TH)beta RF transmit signal QBTX based on receiving and amplifying thesecond RF input signal SRFI. The one of the transmit signals FATX, SATX,PATX, FBTX, SBTX, QBTX that is selected may be based on the PAconfiguration control signal PCC. Additionally, the RF modulation andcontrol circuitry 28 may provide a DC configuration control signal DCCto the DC-DC converter 32. Certain configurations of the DC-DC converter32 may be based on the DC configuration control signal DCC.

FIG. 5 shows the RF communications system 26 according to anotherembodiment of the RF communications system 26. The RF communicationssystem 26 illustrated in FIG. 5 shows details of the RF modulation andcontrol circuitry 28 and the RF PA circuitry 30 illustrated in FIG. 4.Additionally, the RF communications system 26 illustrated in FIG. 5further includes transceiver circuitry 34, front-end aggregationcircuitry 36, and the antenna 18. The transceiver circuitry 34 includesdown-conversion circuitry 38, baseband processing circuitry 40, and theRF modulation and control circuitry 28, which includes control circuitry42 and RF modulation circuitry 44. The RF PA circuitry 30 includes afirst transmit path 46 and a second transmit path 48. The first transmitpath 46 includes a first RF PA 50 and alpha switching circuitry 52. Thesecond transmit path 48 includes a second RF PA 54 and beta switchingcircuitry 56. The front-end aggregation circuitry 36 is coupled to theantenna 18. The control circuitry 42 provides the aggregation controlsignal ACS to the front-end aggregation circuitry 36. Configuration ofthe front-end aggregation circuitry 36 may be based on the aggregationcontrol signal ACS. As such, configuration of the front-end aggregationcircuitry 36 may be controlled by the control circuitry 42 via theaggregation control signal ACS.

The control circuitry 42 provides the envelope control signal ECS andthe DC configuration control signal DCC to the DC-DC converter 32.Further, the control circuitry 42 provides the PA configuration controlsignal PCC to the RF PA circuitry 30. As such, the control circuitry 42may control configuration of the RF PA circuitry 30 via the PAconfiguration control signal PCC and may control a magnitude of theenvelope power supply signal EPS via the envelope control signal ECS.The control circuitry 42 may select one of multiple communicationsmodes, which may include a first half-duplex transmit mode, a firsthalf-duplex receive mode, a second half-duplex transmit mode, a secondhalf-duplex receive mode, a first full-duplex mode, a second full-duplexmode, at least one linear mode, at least one non-linear mode, multipleRF modulation modes, or any combination thereof. Further, the controlcircuitry 42 may select one of multiple frequency bands. The controlcircuitry 42 may provide the aggregation control signal ACS to thefront-end aggregation circuitry 36 based on the selected mode and theselected frequency band. The front-end aggregation circuitry 36 mayinclude various RF components, including RF switches; RF filters, suchas bandpass filters, harmonic filters, and duplexers; RF amplifiers,such as low noise amplifiers (LNAs); impedance matching circuitry; thelike; or any combination thereof. In this regard, routing of RF receivesignals and RF transmit signals through the RF components may be basedon the selected mode and the selected frequency band as directed by theaggregation control signal ACS.

The down-conversion circuitry 38 may receive the first RF receive signalFRX, the second RF receive signal SRX, and up to and including theM^(TH) RF receive signal MRX from the antenna 18 via the front-endaggregation circuitry 36. Each of the RF receive signals FRX, SRX, MRXmay be associated with at least one selected mode, at least one selectedfrequency band, or both. The down-conversion circuitry 38 maydown-convert any of the RF receive signals FRX, SRX, MRX to basebandreceive signals, which may be forwarded to the baseband processingcircuitry 40 for processing. The baseband processing circuitry 40 mayprovide baseband transmit signals to the RF modulation circuitry 44,which may RF modulate the baseband transmit signals to provide the firstRF input signal FRFI or the second RF input signal SRFI to the first RFPA 50 or the second RF PA 54, respectively, depending on the selectedcommunications mode.

The first RF PA 50 may receive and amplify the first RF input signalFRFI to provide the first RF output signal FRFO to the alpha switchingcircuitry 52. Similarly, the second RF PA 54 may receive and amplify thesecond RF input signal SRFI to provide the second RF output signal SRFOto the beta switching circuitry 56. The first RF PA 50 and the second RFPA 54 may receive the envelope power supply signal EPS, which mayprovide power for amplification of the first RF input signal FRFI andthe second RF input signal SRFI, respectively. The alpha switchingcircuitry 52 may forward the first RF output signal FRFO to provide oneof the alpha transmit signals FATX, SATX, PATX to the antenna 18 via thefront-end aggregation circuitry 36, depending on the selectedcommunications mode based on the PA configuration control signal PCC.Similarly, the beta switching circuitry 56 may forward the second RFoutput signal SRFO to provide one of the beta transmit signals FBTX,SBTX, QBTX to the antenna 18 via the front-end aggregation circuitry 36,depending on the selected communications mode based on the PAconfiguration control signal PCC.

FIG. 6 shows the RF communications system 26 according to a furtherembodiment of the RF communications system 26. The RF communicationssystem 26 illustrated in FIG. 6 is similar to the RF communicationssystem 26 illustrated in FIG. 5, except in the RF communications system26 illustrated in FIG. 6, the transceiver circuitry 34 includes acontrol circuitry digital communications interface (DCI) 58, the RF PAcircuitry 30 includes a PA-DCI 60, the DC-DC converter 32 includes aDC-DC converter DCI 62, and the front-end aggregation circuitry 36includes an aggregation circuitry DCI 64. The front-end aggregationcircuitry 36 includes an antenna port AP, which is coupled to theantenna 18. In one embodiment of the RF communications system 26, theantenna port AP is directly coupled to the antenna 18. In one embodimentof the RF communications system 26, the front-end aggregation circuitry36 is coupled between the alpha switching circuitry 52 and the antennaport AP. Further, the front-end aggregation circuitry 36 is coupledbetween the beta switching circuitry 56 and the antenna port AP. Thealpha switching circuitry 52 may be multi-mode multi-band alphaswitching circuitry and the beta switching circuitry 56 may bemulti-mode multi-band beta switching circuitry.

The DCIs 58, 60, 62, 64 are coupled to one another using a digitalcommunications bus 66. In the digital communications bus 66 illustratedin FIG. 6, the digital communications bus 66 is a uni-directional bus inwhich the control circuitry DCI 58 may communicate information to thePA-DCI 60, the DC-DC converter DCI 62, the aggregation circuitry DCI 64,or any combination thereof. As such, the control circuitry 42 mayprovide the envelope control signal ECS and the DC configuration controlsignal DCC via the control circuitry DCI 58 to the DC-DC converter 32via the DC-DC converter DCI 62. Similarly, the control circuitry 42 mayprovide the aggregation control signal ACS via the control circuitry DCI58 to the front-end aggregation circuitry 36 via the aggregationcircuitry DCI 64. Additionally, the control circuitry 42 may provide thePA configuration control signal PCC via the control circuitry DCI 58 tothe RF PA circuitry 30 via the PA-DCI 60.

FIG. 7 shows the RF communications system 26 according to one embodimentof the RF communications system 26. The RF communications system 26illustrated in FIG. 7 is similar to the RF communications system 26illustrated in FIG. 6, except in the RF communications system 26illustrated in FIG. 7, the digital communications bus 66 is abi-directional bus and each of the DCIs 58, 60, 62, 64 is capable ofreceiving or transmitting information. In alternate embodiments of theRF communications system 26, any or all of the DCIs 58, 60, 62, 64 maybe uni-directional and any or all of the DCIs 58, 60, 62, 64 may bebi-directional.

FIG. 8 shows details of the RF PA circuitry 30 illustrated in FIG. 5according to one embodiment of the RF PA circuitry 30. Specifically,FIG. 8 shows details of the alpha switching circuitry 52 and the betaswitching circuitry 56 according to one embodiment of the alphaswitching circuitry 52 and the beta switching circuitry 56. The alphaswitching circuitry 52 includes an alpha RF switch 68 and a first alphaharmonic filter 70. The beta switching circuitry 56 includes a beta RFswitch 72 and a first beta harmonic filter 74. Configuration of thealpha RF switch 68 and the beta RF switch 72 may be based on the PAconfiguration control signal PCC. In one communications mode, such as analpha half-duplex transmit mode, an alpha saturated mode, or an alphanon-linear mode, the alpha RF switch 68 is configured to forward thefirst RF output signal FRFO to provide the first alpha RF transmitsignal FATX via the first alpha harmonic filter 70. In anothercommunications mode, such as an alpha full-duplex mode or an alphalinear mode, the alpha RF switch 68 is configured to forward the firstRF output signal FRFO to provide any of the second alpha RF transmitsignal SATX through the P^(TH) alpha RF transmit signal PATX. When aspecific RF band is selected, the alpha RF switch 68 may be configuredto provide a corresponding selected one of the second alpha RF transmitsignal SATX through the P^(TH) alpha RF transmit signal PATX.

In one communications mode, such as a beta half-duplex transmit mode, abeta saturated mode, or a beta non-linear mode, the beta RF switch 72 isconfigured to forward the second RF output signal SRFO to provide thefirst beta RF transmit signal FBTX via the first beta harmonic filter74. In another communications mode, such as a beta full-duplex mode or abeta linear mode, the beta RF switch 72 is configured to forward thesecond RF output signal SRFO to provide any of the second beta RFtransmit signal SBTX through the Q^(TH) beta RF transmit signal QBTX.When a specific RF band is selected, beta RF switch 72 may be configuredto provide a corresponding selected one of the second beta RF transmitsignal SBTX through the Q^(TH) beta RF transmit signal QBTX. The firstalpha harmonic filter 70 may be used to filter out harmonics of an RFcarrier in the first RF output signal FRFO. The first beta harmonicfilter 74 may be used to filter out harmonics of an RF carrier in thesecond RF output signal SRFO.

FIG. 9 shows details of the RF PA circuitry 30 illustrated in FIG. 5according to an alternate embodiment of the RF PA circuitry 30.Specifically, FIG. 9 shows details of the alpha switching circuitry 52and the beta switching circuitry 56 according to an alternate embodimentof the alpha switching circuitry 52 and the beta switching circuitry 56.The alpha switching circuitry 52 includes the alpha RF switch 68, thefirst alpha harmonic filter 70, and a second alpha harmonic filter 76.The beta switching circuitry 56 includes the beta RF switch 72, thefirst beta harmonic filter 74, and a second beta harmonic filter 78.Configuration of the alpha RF switch 68 and the beta RF switch 72 may bebased on the PA configuration control signal PCC. In one communicationsmode, such as a first alpha half-duplex transmit mode, a first alphasaturated mode, or a first alpha non-linear mode, the alpha RF switch 68is configured to forward the first RF output signal FRFO to provide thefirst alpha RF transmit signal FATX via the first alpha harmonic filter70. In another communications mode, such as a second alpha half-duplextransmit mode, a second alpha saturated mode, or a second alphanon-linear mode, the alpha RF switch 68 is configured to forward thefirst RF output signal FRFO to provide the second alpha RF transmitsignal SATX via the second alpha harmonic filter 76. In an alternatecommunications mode, such as an alpha full-duplex mode or an alphalinear mode, the alpha RF switch 68 is configured to forward the firstRF output signal FRFO to provide any of a third alpha RF transmit signalTATX through the P^(TH) alpha RF transmit signal PATX. When a specificRF band is selected, the alpha RF switch 68 may be configured to providea corresponding selected one of the third alpha RF transmit signal TATXthrough the P^(TH) alpha RF transmit signal PATX.

In one communications mode, such as a first beta half-duplex transmitmode, a first beta saturated mode, or a first beta non-linear mode, thebeta RF switch 72 is configured to forward the second RF output signalSRFO to provide the first beta RF transmit signal FBTX via the firstbeta harmonic filter 74. In another communications mode, such as asecond beta half-duplex transmit mode, a second beta saturated mode, ora second beta non-linear mode, the beta RF switch 72 is configured toforward the second RF output signal SRFO to provide the second beta RFtransmit signal SBTX via the second beta harmonic filter 78. In analternate communications mode, such as a beta full-duplex mode or a betalinear mode, the beta RF switch 72 is configured to forward the secondRF output signal SRFO to provide any of a third beta RF transmit signalTBTX through the Q^(TH) beta RF transmit signal QBTX. When a specific RFband is selected, the beta RF switch 72 may be configured to provide acorresponding selected one of the third beta RF transmit signal TBTXthrough the Q^(TH) beta RF transmit signal QBTX. The first alphaharmonic filter 70 or the second alpha harmonic filter 76 may be used tofilter out harmonics of an RF carrier in the first RF output signalFRFO. The first beta harmonic filter 74 or the second beta harmonicfilter 78 may be used to filter out harmonics of an RF carrier in thesecond RF output signal SRFO.

FIG. 10 shows the RF communications system 26 according to oneembodiment of the RF communications system 26. The RF communicationssystem 26 shown in FIG. 10 is similar to the RF communications system 26shown in FIG. 4, except the RF communications system 26 illustrated inFIG. 10 further includes a DC power supply 80 and the DC configurationcontrol signal DCC is omitted. Additionally, details of the DC-DCconverter 32 are shown according to one embodiment of the DC-DCconverter 32. The DC-DC converter 32 includes first power filteringcircuitry 82, a charge pump buck converter 84, a buck converter 86,second power filtering circuitry 88, a first inductive element L1, and asecond inductive element L2. The DC power supply 80 provides a DC powersupply signal DCPS to the charge pump buck converter 84, the buckconverter 86, and the second power filtering circuitry 88. In oneembodiment of the DC power supply 80, the DC power supply 80 is abattery.

The second power filtering circuitry 88 is coupled to the RF PAcircuitry 30 and to the DC power supply 80. The charge pump buckconverter 84 is coupled to the DC power supply 80. The first inductiveelement L1 is coupled between the charge pump buck converter 84 and thefirst power filtering circuitry 82. The buck converter 86 is coupled tothe DC power supply 80. The second inductive element L2 is coupledbetween the buck converter 86 and the first power filtering circuitry82. The first power filtering circuitry 82 is coupled to the RF PAcircuitry 30. One end of the first inductive element L1 is coupled toone end of the second inductive element L2 at the first power filteringcircuitry 82.

In one embodiment of the DC-DC converter 32, the DC-DC converter 32operates in one of multiple converter operating modes, which include afirst converter operating mode, a second converter operating mode, and athird converter operating mode. In an alternate embodiment of the DC-DCconverter 32, the DC-DC converter 32 operates in one of the firstconverter operating mode and the second converter operating mode. In thefirst converter operating mode, the charge pump buck converter 84 isactive, such that the envelope power supply signal EPS is based on theDC power supply signal DCPS via the charge pump buck converter 84, andthe first inductive element L1. In the first converter operating mode,the buck converter 86 is inactive and does not contribute to theenvelope power supply signal EPS. In the second converter operatingmode, the buck converter 86 is active, such that the envelope powersupply signal EPS is based on the DC power supply signal DCPS via thebuck converter 86 and the second inductive element L2. In the secondconverter operating mode, the charge pump buck converter 84 is inactive,such that the charge pump buck converter 84 does not contribute to theenvelope power supply signal EPS. In the third converter operating mode,the charge pump buck converter 84 and the buck converter 86 are active,such that either the charge pump buck converter 84; the buck converter86; or both may contribute to the envelope power supply signal EPS. Assuch, in the third converter operating mode, the envelope power supplysignal EPS is based on the DC power supply signal DCPS either via thecharge pump buck converter 84, and the first inductive element L1; viathe buck converter 86 and the second inductive element L2; or both.

The second power filtering circuitry 88 filters the DC power supplysignal DCPS to provide the bias power supply signal BPS. The secondpower filtering circuitry 88 may function as a lowpass filter byremoving ripple, noise, and the like from the DC power supply signalDCPS to provide the bias power supply signal BPS. As such, in oneembodiment of the DC-DC converter 32, the bias power supply signal BPSis based on the DC power supply signal DCPS.

In the first converter operating mode or the third converter operatingmode, the charge pump buck converter 84 may receive, charge pump, andbuck convert the DC power supply signal DCPS to provide a first buckoutput signal FBO to the first inductive element L1. As such, in oneembodiment of the charge pump buck converter 84, the first buck outputsignal FBO is based on the DC power supply signal DCPS. Further, thefirst inductive element L1 may function as a first energy transferelement of the charge pump buck converter 84 to transfer energy via thefirst buck output signal FBO to the first power filtering circuitry 82.In the first converter operating mode or the third converter operatingmode, the first inductive element L1 and the first power filteringcircuitry 82 may receive and filter the first buck output signal FBO toprovide the envelope power supply signal EPS. The charge pump buckconverter 84 may regulate the envelope power supply signal EPS bycontrolling the first buck output signal FBO based on a setpoint of theenvelope power supply signal EPS provided by the envelope control signalECS.

In the second converter operating mode or the third converter operatingmode, the buck converter 86 may receive and buck convert the DC powersupply signal DCPS to provide a second buck output signal SBO to thesecond inductive element L2. As such, in one embodiment of the buckconverter 86, the second buck output signal SBO is based on the DC powersupply signal DCPS. Further, the second inductive element L2 mayfunction as a second energy transfer element of the buck converter 86 totransfer energy via the first power filtering circuitry 82 to the firstpower filtering circuitry 82. In the second converter operating mode orthe third converter operating mode, the second inductive element L2 andthe first power filtering circuitry 82 may receive and filter the secondbuck output signal SBO to provide the envelope power supply signal EPS.The buck converter 86 may regulate the envelope power supply signal EPSby controlling the second buck output signal SBO based on a setpoint ofthe envelope power supply signal EPS provided by the envelope controlsignal ECS.

In one embodiment of the charge pump buck converter 84, the charge pumpbuck converter 84 operates in one of multiple pump buck operating modes.During a pump buck pump-up operating mode of the charge pump buckconverter 84, the charge pump buck converter 84 pumps-up the DC powersupply signal DCPS to provide an internal signal (not shown), such thata voltage of the internal signal is greater than a voltage of the DCpower supply signal DCPS. In an alternate embodiment of the charge pumpbuck converter 84, during the pump buck pump-up operating mode, avoltage of the envelope power supply signal EPS is greater than thevoltage of the DC power supply signal DCPS. During a pump buck pump-downoperating mode of the charge pump buck converter 84, the charge pumpbuck converter 84 pumps-down the DC power supply signal DCPS to providethe internal signal, such that a voltage of the internal signal is lessthan a voltage of the DC power supply signal DCPS. In an alternateembodiment of the charge pump buck converter 84, during the pump buckpump-down operating mode, the voltage of the envelope power supplysignal EPS is less than the voltage of the DC power supply signal DCPS.During a pump buck pump-even operating mode of the charge pump buckconverter 84, the charge pump buck converter 84 pumps the DC powersupply signal DCPS to the internal signal, such that a voltage of theinternal signal is about equal to a voltage of the DC power supplysignal DCPS. One embodiment of the DC-DC converter 32 includes a pumpbuck bypass operating mode of the charge pump buck converter 84, suchthat during the pump buck bypass operating mode, the charge pump buckconverter 84 by-passes charge pump circuitry (not shown) using by-passcircuitry (not shown) to forward the DC power supply signal DCPS toprovide the internal signal, such that a voltage of the internal isabout equal to a voltage of the DC power supply signal DCPS.

In one embodiment of the charge pump buck converter 84, the pump buckoperating modes include the pump buck pump-up operating mode, the pumpbuck pump-down operating mode, the pump buck pump-even operating mode,and the pump buck bypass operating mode. In an alternate embodiment ofthe charge pump buck converter 84, the pump buck pump-even operatingmode is omitted. In an additional embodiment of the charge pump buckconverter 84, the pump buck bypass operating mode is omitted. In anotherembodiment of the charge pump buck converter 84, the pump buck pump-downoperating mode is omitted. In a further embodiment of the charge pumpbuck converter 84, any or all of the pump buck pump-up operating mode,the pump buck pump-down operating mode, the pump buck pump-evenoperating mode, and the pump buck bypass operating mode are omitted. Ina supplemental embodiment of the charge pump buck converter 84, thecharge pump buck converter 84 operates in only the pump buck pump-upoperating mode. In an additional embodiment of the charge pump buckconverter 84, the charge pump buck converter 84 operates in one of thepump buck pump-up operating mode and at least one other pump buckoperating mode of the charge pump buck converter 84. The at least oneother pump buck operating mode of the charge pump buck converter 84 mayinclude any or all of the pump buck pump-up operating mode, the pumpbuck pump-down operating mode, the pump buck pump-even operating mode,and the pump buck bypass operating mode.

FIG. 11 shows the RF communications system 26 according to an alternateembodiment of the RF communications system 26. The RF communicationssystem 26 illustrated in FIG. 11 is similar to the RF communicationssystem 26 illustrated in FIG. 10, except in the RF communications system26 illustrated in FIG. 11, the DC-DC converter 32 further includes DC-DCcontrol circuitry 90 and a charge pump 92, and omits the secondinductive element L2. Instead of the second power filtering circuitry 88being coupled to the DC power supply 80 as shown in FIG. 10, the chargepump 92 is coupled to the DC power supply 80, such that the charge pump92 is coupled between the DC power supply 80 and the second powerfiltering circuitry 88. Additionally, the RF modulation and controlcircuitry 28 provides the DC configuration control signal DCC and theenvelope control signal ECS to the DC-DC control circuitry 90.

The DC-DC control circuitry 90 provides a charge pump buck controlsignal CPBS to the charge pump buck converter 84, provides a buckcontrol signal BCS to the buck converter 86, and provides a charge pumpcontrol signal CPS to the charge pump 92. The charge pump buck controlsignal CPBS, the buck control signal BCS, or both may indicate whichconverter operating mode is selected. Further, the charge pump buckcontrol signal CPBS, the buck control signal BCS, or both may providethe setpoint of the envelope power supply signal EPS as provided by theenvelope control signal ECS. The charge pump buck control signal CPBSmay indicate which pump buck operating mode is selected.

In one embodiment of the DC-DC converter 32, selection of the converteroperating mode is made by the DC-DC control circuitry 90. In analternate embodiment of the DC-DC converter 32, selection of theconverter operating mode is made by the RF modulation and controlcircuitry 28 and may be communicated to the DC-DC converter 32 via theDC configuration control signal DCC. In an additional embodiment of theDC-DC converter 32, selection of the converter operating mode is made bythe control circuitry 42 (FIG. 5) and may be communicated to the DC-DCconverter 32 via the DC configuration control signal DCC. In general,selection of the converter operating mode is made by control circuitry,which may be any of the DC-DC control circuitry 90, the RF modulationand control circuitry 28, and the control circuitry 42 (FIG. 5).

In one embodiment of the DC-DC converter 32, selection of the pump buckoperating mode is made by the DC-DC control circuitry 90. In analternate embodiment of the DC-DC converter 32, selection of the pumpbuck operating mode is made by the RF modulation and control circuitry28 and communicated to the DC-DC converter 32 via the DC configurationcontrol signal DCC. In an additional embodiment of the DC-DC converter32, selection of the pump buck operating mode is made by the controlcircuitry 42 (FIG. 5) and communicated to the DC-DC converter 32 via theDC configuration control signal DCC. In general, selection of the pumpbuck operating mode is made by control circuitry, which may be any ofthe DC-DC control circuitry 90, the RF modulation and control circuitry28, and the control circuitry 42 (FIG. 5). As such, the controlcircuitry may select one of the pump buck pump-up operating mode and atleast one other pump buck operating mode of the charge pump buckconverter 84. The at least one other pump buck operating mode of thecharge pump buck converter 84 may include any or all of the pump buckpump-down operating mode, the pump buck pump-even operating mode, andthe pump buck bypass operating mode.

The charge pump 92 may operate in one of multiple bias supply pumpoperating modes. During a bias supply pump-up operating mode of thecharge pump 92, the charge pump 92 receives and pumps-up the DC powersupply signal DCPS to provide the bias power supply signal BPS, suchthat a voltage of the bias power supply signal BPS is greater than avoltage of the DC power supply signal DCPS. During a bias supplypump-down operating mode of the charge pump 92, the charge pump 92pumps-down the DC power supply signal DCPS to provide the bias powersupply signal BPS, such that a voltage of the bias power supply signalBPS is less than a voltage of the DC power supply signal DCPS. During abias supply pump-even operating mode of the charge pump 92, the chargepump 92 pumps the DC power supply signal DCPS to provide the bias powersupply signal BPS, such that a voltage of the bias power supply signalBPS is about equal to a voltage of the DC power supply signal DCPS. Oneembodiment of the DC-DC converter 32 includes a bias supply bypassoperating mode of the charge pump 92, such that during the bias supplybypass operating mode, the charge pump 92 by-passes charge pumpcircuitry (not shown) using by-pass circuitry (not shown) to forward theDC power supply signal DCPS to provide the bias power supply signal BPS,such that a voltage of the bias power supply signal BPS is about equalto a voltage of the DC power supply signal DCPS. The charge pump controlsignal CPS may indicate which bias supply pump operating mode isselected.

In one embodiment of the charge pump 92, the bias supply pump operatingmodes include the bias supply pump-up operating mode, the bias supplypump-down operating mode, the bias supply pump-even operating mode, andthe bias supply bypass operating mode. In an alternate embodiment of thecharge pump 92, the bias supply pump-even operating mode is omitted. Inan additional embodiment of the charge pump 92, the bias supply bypassoperating mode is omitted. In another embodiment of the charge pump 92,the bias supply pump-down operating mode is omitted. In a furtherembodiment of the charge pump 92, any or all of the bias supply pump-upoperating mode, the bias supply pump-down operating mode, the biassupply pump-even operating mode, and the bias supply bypass operatingmode are omitted. In a supplemental embodiment of the charge pump 92,the charge pump 92 operates in only the bias supply pump-up operatingmode. In an additional embodiment of the charge pump 92, the charge pump92 operates in the bias supply pump-up operating mode and at least oneother operating mode of the charge pump 92, which may include any or allof the bias supply pump-down operating mode, the bias supply pump-evenoperating mode, and the bias supply bypass operating mode.

In one embodiment of the DC-DC converter 32, selection of the biassupply pump operating mode is made by the DC-DC control circuitry 90. Inan alternate embodiment of the DC-DC converter 32, selection of the biassupply pump operating mode is made by the RF modulation and controlcircuitry 28 and communicated to the DC-DC converter 32 via the DCconfiguration control signal DCC. In an additional embodiment of theDC-DC converter 32, selection of the bias supply pump operating mode ismade by the control circuitry 42 (FIG. 5) and communicated to the DC-DCconverter 32 via the DC configuration control signal DCC. In general,selection of the bias supply pump operating mode is made by controlcircuitry, which may be any of the DC-DC control circuitry 90, the RFmodulation and control circuitry 28, and the control circuitry 42 (FIG.5). As such, the control circuitry may select one of the bias supplypump-up operating mode and at least one other bias supply operatingmode. The at least one other bias supply operating mode may include anyor all of the bias supply pump-down operating mode, the bias supplypump-even operating mode, and the bias supply bypass operating mode.

The second power filtering circuitry 88 filters the bias power supplysignal BPS. The second power filtering circuitry 88 may function as alowpass filter by removing ripple, noise, and the like to provide thebias power supply signal BPS. As such, in one embodiment of the DC-DCconverter 32, the bias power supply signal BPS is based on the DC powersupply signal DCPS.

Regarding omission of the second inductive element L2, instead of thesecond inductive element L2 coupled between the buck converter 86 andthe first power filtering circuitry 82 as shown in FIG. 10, one end ofthe first inductive element L1 is coupled to both the charge pump buckconverter 84 and the buck converter 86. As such, in the second converteroperating mode or the third converter operating mode, the buck converter86 may receive and buck convert the DC power supply signal DCPS toprovide the second buck output signal SBO to the first inductive elementL1. As such, in one embodiment of the charge pump buck converter 84, thesecond buck output signal SBO is based on the DC power supply signalDCPS. Further, the first inductive element L1 may function as a firstenergy transfer element of the buck converter 86 to transfer energy viathe second buck output signal SBO to the first power filtering circuitry82. In the first converter operating mode, the second converteroperating mode, or the third converter operating mode, the firstinductive element L1 and the first power filtering circuitry 82 receiveand filter the first buck output signal FBO, the second buck outputsignal SBO, or both to provide the envelope power supply signal EPS.

FIG. 12 shows details of the DC-DC converter 32 illustrated in FIG. 11according to an alternate embodiment of the DC-DC converter 32. TheDC-DC converter 32 illustrated in FIG. 12 is similar to the DC-DCconverter 32 illustrated in FIG. 10, except the DC-DC converter 32illustrated in FIG. 12 shows details of the first power filteringcircuitry 82 and the second power filtering circuitry 88. Further, theDC-DC converter 32 illustrated in FIG. 12 includes the DC-DC controlcircuitry 90 and the charge pump 92 as shown in FIG. 11.

The first power filtering circuitry 82 includes a first capacitiveelement C1, a second capacitive element C2, and a third inductiveelement L3. The first capacitive element C1 is coupled between one endof the third inductive element L3 and a ground. The second capacitiveelement C2 is coupled between an opposite end of the third inductiveelement L3 and ground. The one end of the third inductive element L3 iscoupled to one end of the first inductive element L1. Further, the oneend of the third inductive element L3 is coupled to one end of thesecond inductive element L2. In an additional embodiment of the DC-DCconverter 32, the second inductive element L2 is omitted. The oppositeend of the third inductive element L3 is coupled to the RF PA circuitry30. As such, the opposite end of the third inductive element L3 and oneend of the second capacitive element C2 provide the envelope powersupply signal EPS. In an alternate embodiment of the first powerfiltering circuitry 82, the third inductive element L3, the secondcapacitive element C2, or both are omitted.

FIG. 13 shows details of the RF PA circuitry 30 illustrated in FIG. 5according to one embodiment of the RF PA circuitry 30. The RF PAcircuitry 30 illustrated in FIG. 13 is similar to the RF PA circuitry 30illustrated in FIG. 5, except the RF PA circuitry 30 illustrated in FIG.13 further includes PA control circuitry 94, PA bias circuitry 96, andswitch driver circuitry 98. The PA bias circuitry 96 is coupled betweenthe PA control circuitry 94 and the RF PAs 50, 54. The switch drivercircuitry 98 is coupled between the PA control circuitry 94 and theswitching circuitry 52, 56. The PA control circuitry 94 receives the PAconfiguration control signal PCC, provides a bias configuration controlsignal BCC to the PA bias circuitry 96 based on the PA configurationcontrol signal PCC, and provides a switch configuration control signalSCC to the switch driver circuitry 98 based on the PA configurationcontrol signal PCC. The switch driver circuitry 98 provides any neededdrive signals to configure the alpha switching circuitry 52 and the betaswitching circuitry 56.

The PA bias circuitry 96 receives the bias power supply signal BPS andthe bias configuration control signal BCC. The PA bias circuitry 96provides a first driver bias signal FDB and a first final bias signalFFB to the first RF PA 50 based on the bias power supply signal BPS andthe bias configuration control signal BCC. The PA bias circuitry 96provides a second driver bias signal SDB and a second final bias signalSFB to the second RF PA 54 based on the bias power supply signal BPS andthe bias configuration control signal BCC. The bias power supply signalBPS provides the power necessary to generate the bias signals FDB, FFB,SDB, SFB. A selected magnitude of each of the bias signals FDB, FFB,SDB, SFB is provided by the PA bias circuitry 96. In one embodiment ofthe RF PA circuitry 30, the PA control circuitry 94 selects themagnitude of any or all of the bias signals FDB, FFB, SDB, SFB andcommunicates the magnitude selections to the PA bias circuitry 96 viathe bias configuration control signal BCC. The magnitude selections bythe PA control circuitry 94 may be based on the PA configuration controlsignal PCC. In an alternate embodiment of the RF PA circuitry 30, thecontrol circuitry 42 (FIG. 5) selects the magnitude of any or all of thebias signals FDB, FFB, SDB, SFB and communicates the magnitudeselections to the PA bias circuitry 96 via the PA control circuitry 94.

In one embodiment of the RF PA circuitry 30, the RF PA circuitry 30operates in one of a first PA operating mode and a second PA operatingmode. During the first PA operating mode, the first transmit path 46 isenabled and the second transmit path 48 is disabled. During the secondPA operating mode, the first transmit path 46 is disabled and the secondtransmit path 48 is enabled. In one embodiment of the first RF PA 50 andthe second RF PA 54, during the second PA operating mode, the first RFPA 50 is disabled, and during the first PA operating mode, the second RFPA 54 is disabled. In one embodiment of the alpha switching circuitry 52and the beta switching circuitry 56, during the second PA operatingmode, the alpha switching circuitry 52 is disabled, and during the firstPA operating mode, the beta switching circuitry 56 is disabled.

In one embodiment of the first RF PA 50, during the second PA operatingmode, the first RF PA 50 is disabled via the first driver bias signalFDB. In an alternate embodiment of the first RF PA 50, during the secondPA operating mode, the first RF PA 50 is disabled via the first finalbias signal FFB. In an additional embodiment of the first RF PA 50,during the second PA operating mode, the first RF PA 50 is disabled viaboth the first driver bias signal FDB and the first final bias signalFFB. In one embodiment of the second RF PA 54, during the first PAoperating mode, the second RF PA 54 is disabled via the second driverbias signal SDB. In an alternate embodiment of the second RF PA 54,during the first PA operating mode, the second RF PA 54 is disabled viathe second final bias signal SFB. In an additional embodiment of thesecond RF PA 54, during the first PA operating mode, the second RF PA 54is disabled via both the second driver bias signal SDB and the secondfinal bias signal SFB.

In one embodiment of the RF PA circuitry 30, the PA control circuitry 94selects the one of the first PA operating mode and the second PAoperating mode. As such, the PA control circuitry 94 may control any orall of the bias signals FDB, FFB, SDB, SFB via the bias configurationcontrol signal BCC based on the PA operating mode selection. Further,the PA control circuitry 94 may control the switching circuitry 52, 56via the switch configuration control signal SCC based on the PAoperating mode selection. The PA operating mode selection may be basedon the PA configuration control signal PCC. In an alternate embodimentof the RF PA circuitry 30, the control circuitry 42 (FIG. 5) selects theone of the first PA operating mode and the second PA operating mode. Assuch, the control circuitry 42 (FIG. 5) may indicate the operating modeselection to the PA control circuitry 94 via the PA configurationcontrol signal PCC. In an additional embodiment of the RF PA circuitry30, the RF modulation and control circuitry 28 (FIG. 5) selects the oneof the first PA operating mode and the second PA operating mode. Assuch, the RF modulation and control circuitry 28 (FIG. 5) may indicatethe operating mode selection to the PA control circuitry 94 via the PAconfiguration control signal PCC. In general, selection of the PAoperating mode is made by control circuitry, which may be any of the PAcontrol circuitry 94, the RF modulation and control circuitry 28 (FIG.5), and the control circuitry 42 (FIG. 5).

FIG. 14 shows details of the RF PA circuitry 30 illustrated in FIG. 6according to an alternate embodiment of the RF PA circuitry 30. The RFPA circuitry 30 illustrated in FIG. 14 is similar to the RF PA circuitry30 illustrated in FIG. 13, except the RF PA circuitry 30 illustrated inFIG. 14 further includes the PA-DCI 60, which is coupled to the PAcontrol circuitry 94 and to the digital communications bus 66. As such,the control circuitry 42 (FIG. 6) may provide the PA configurationcontrol signal PCC via the control circuitry DCI 58 (FIG. 6) to the PAcontrol circuitry 94 via the PA-DCI 60.

FIG. 15 shows details of the first RF PA 50 and the second RF PA 54illustrated in FIG. 13 according one embodiment of the first RF PA 50and the second RF PA 54. The first RF PA 50 includes a firstnon-quadrature PA path 100 and a first quadrature PA path 102. Thesecond RF PA 54 includes a second non-quadrature PA path 104 and asecond quadrature PA path 106. In one embodiment of the first RF PA 50,the first quadrature PA path 102 is coupled between the firstnon-quadrature PA path 100 and the antenna port AP (FIG. 6), which iscoupled to the antenna 18 (FIG. 6). In an alternate embodiment of thefirst RF PA 50, the first non-quadrature PA path 100 is omitted, suchthat the first quadrature PA path 102 is coupled to the antenna port AP(FIG. 6). The first quadrature PA path 102 may be coupled to the antennaport AP (FIG. 6) via the alpha switching circuitry 52 (FIG. 6) and thefront-end aggregation circuitry 36 (FIG. 6). The first non-quadrature PApath 100 may include any number of non-quadrature gain stages. The firstquadrature PA path 102 may include any number of quadrature gain stages.In one embodiment of the second RF PA 54, the second quadrature PA path106 is coupled between the second non-quadrature PA path 104 and theantenna port AP (FIG. 6). In an alternate embodiment of the second RF PA54, the second non-quadrature PA path 104 is omitted, such that thesecond quadrature PA path 106 is coupled to the antenna port AP (FIG.6). The second quadrature PA path 106 may be coupled to the antenna portAP (FIG. 6) via the beta switching circuitry 56 (FIG. 6) and thefront-end aggregation circuitry 36 (FIG. 6). The second non-quadraturePA path 104 may include any number of non-quadrature gain stages. Thesecond quadrature PA path 106 may include any number of quadrature gainstages.

In one embodiment of the RF communications system 26, the controlcircuitry 42 (FIG. 5) selects one of multiple communications modes,which include a first PA operating mode and a second PA operating mode.During the first PA operating mode, the first PA paths 100, 102 receivethe envelope power supply signal EPS, which provides power foramplification. During the second PA operating mode, the second PA paths104, 106 receive the envelope power supply signal EPS, which providespower for amplification. During the first PA operating mode, the firstnon-quadrature PA path 100 receives the first driver bias signal FDB,which provides biasing to the first non-quadrature PA path 100, and thefirst quadrature PA path 102 receives the first final bias signal FFB,which provides biasing to the first quadrature PA path 102. During thesecond PA operating mode, the second non-quadrature PA path 104 receivesthe second driver bias signal SDB, which provides biasing to the secondnon-quadrature PA path 104, and the second quadrature PA path 106receives the second final bias signal SFB, which provides biasing to thesecond quadrature PA path 106.

The first non-quadrature PA path 100 has a first single-ended output FSOand the first quadrature PA path 102 has a first single-ended input FSI.The first single-ended output FSO may be coupled to the firstsingle-ended input FSI. In one embodiment of the first RF PA 50, thefirst single-ended output FSO is directly coupled to the firstsingle-ended input FSI. The second non-quadrature PA path 104 has asecond single-ended output SSO and the second quadrature PA path 106 hasa second single-ended input SSI. The second single-ended output SSO maybe coupled to the second single-ended input SSI. In one embodiment ofthe second RF PA 54, the second single-ended output SSO is directlycoupled to the second single-ended input SSI.

During the first PA operating mode, the first RF PA 50 receives andamplifies the first RF input signal FRFI to provide the first RF outputsignal FRFO, and the second RF PA 54 is disabled. During the second PAoperating mode, the second RF PA 54 receives and amplifies the second RFinput signal SRFI to provide the second RF output signal SRFO, and thefirst RF PA 50 is disabled. In one embodiment of the RF communicationssystem 26, the first RF input signal FRFI is a highband RF input signaland the second RF input signal SRFI is a lowband RF input signal. In oneexemplary embodiment of the RF communications system 26, a differencebetween a frequency of the highband RF input signal and a frequency ofthe lowband RF input signal is greater than about 500 megahertz, suchthat the frequency of the highband RF input signal is greater than thefrequency of the lowband RF input signal. In an alternate exemplaryembodiment of the RF communications system 26, a ratio of a frequency ofthe highband RF input signal divided by a frequency of the lowband RFinput signal is greater than about 1.5.

In one embodiment of the first RF PA 50, during the first PA operatingmode, the first non-quadrature PA path 100 receives and amplifies thefirst RF input signal FRFI to provide a first RF feeder output signalFFO to the first quadrature PA path 102 via the first single-endedoutput FSO. Further, during the first PA operating mode, the firstquadrature PA path 102 receives and amplifies the first RF feeder outputsignal FFO via the first single-ended input FSI to provide the first RFoutput signal FRFO. In one embodiment of the second RF PA 54, during thesecond PA operating mode, the second non-quadrature PA path 104 receivesand amplifies the second RF input signal SRFI to provide a second RFfeeder output signal SFO to the second quadrature PA path 106 via thesecond single-ended output SSO. Further, during the second PA operatingmode, the second quadrature PA path 106 receives and amplifies thesecond RF feeder output signal SFO via the second single-ended input SSIto provide the second RF output signal SRFO.

Quadrature PA Architecture

A summary of quadrature PA architecture is presented, followed by adetailed description of the quadrature PA architecture according to oneembodiment of the present disclosure. One embodiment of the RFcommunications system 26 (FIG. 6) relates to a quadrature RF PAarchitecture that utilizes a single-ended interface to couple anon-quadrature PA path to a quadrature PA path, which may be coupled tothe antenna port (FIG. 6). The quadrature nature of the quadrature PApath may provide tolerance for changes in antenna loading conditions. AnRF splitter in the quadrature PA path may present a relatively stableinput impedance, which may be predominantly resistive, to thenon-quadrature PA path over a wide frequency range, therebysubstantially isolating the non-quadrature PA path from changes in theantenna loading conditions. Further, the input impedance maysubstantially establish a load line slope of a feeder PA stage in thenon-quadrature PA path, thereby simplifying the quadrature RF PAarchitecture. One embodiment of the quadrature RF PA architecture usestwo separate PA paths, either of which may incorporate a combinednon-quadrature and quadrature PA architecture.

Due to the relatively stable input impedance, RF power measurementstaken at the single-ended interface may provide high directivity andaccuracy. Further, by combining the non-quadrature PA path and thequadrature PA path, gain stages may be eliminated and circuit topologymay be simplified. In one embodiment of the RF splitter, the RF splitteris a quadrature hybrid coupler, which may include a pair of tightlycoupled inductors. The input impedance may be based on inductances ofthe pair of tightly coupled inductors and parasitic capacitance betweenthe inductors. As such, construction of the pair of tightly coupledinductors may be varied to select a specific parasitic capacitance toprovide a specific input impedance. Further, the RF splitter may beintegrated onto one semiconductor die with amplifying elements of thenon-quadrature PA path, with amplifying elements of the quadrature PApath, or both, thereby reducing size and cost. Additionally, thequadrature PA path may have only a single quadrature amplifier stage tofurther simplify the design. In certain embodiments, using only thesingle quadrature amplifier stage provides adequate tolerance forchanges in antenna loading conditions.

FIG. 16 shows details of the first non-quadrature PA path 100 and thesecond non-quadrature PA path 104 illustrated in FIG. 15 according toone embodiment of the first non-quadrature PA path 100 and the secondnon-quadrature PA path 104. The first non-quadrature PA path 100includes a first input PA impedance matching circuit 108, a first inputPA stage 110, a first feeder PA impedance matching circuit 112, and afirst feeder PA stage 114, which provides the first single-ended outputFSO. The first input PA stage 110 is coupled between the first input PAimpedance matching circuit 108 and the first feeder PA impedancematching circuit 112. The first feeder PA stage 114 is coupled betweenthe first feeder PA impedance matching circuit 112 and the firstquadrature PA path 102. The first input PA impedance matching circuit108 may provide at least an approximate impedance match between the RFmodulation circuitry 44 (FIG. 5) and the first input PA stage 110. Thefirst feeder PA impedance matching circuit 112 may provide at least anapproximate impedance match between the first input PA stage 110 and thefirst feeder PA stage 114. In alternate embodiments of the firstnon-quadrature PA path 100, any or all of the first input PA impedancematching circuit 108, the first input PA stage 110, and the first feederPA impedance matching circuit 112, may be omitted.

During the first PA operating mode, the first input PA impedancematching circuit 108 receives and forwards the first RF input signalFRFI to the first input PA stage 110. During the first PA operatingmode, the first input PA stage 110 receives and amplifies the forwardedfirst RF input signal FRFI to provide a first RF feeder input signal FFIto the first feeder PA stage 114 via the first feeder PA impedancematching circuit 112. During the first PA operating mode, the firstfeeder PA stage 114 receives and amplifies the first RF feeder inputsignal FFI to provide the first RF feeder output signal FFO via thefirst single-ended output FSO. The first feeder PA stage 114 may have afirst output load line having a first load line slope. During the firstPA operating mode, the envelope power supply signal EPS provides powerfor amplification to the first input PA stage 110 and to the firstfeeder PA stage 114. During the first PA operating mode, the firstdriver bias signal FDB provides biasing to the first input PA stage 110and the first feeder PA stage 114.

The second non-quadrature PA path 104 includes a second input PAimpedance matching circuit 116, a second input PA stage 118, a secondfeeder PA impedance matching circuit 120, and a second feeder PA stage122, which provides the second single-ended output SSO. The second inputPA stage 118 is coupled between the second input PA impedance matchingcircuit 116 and the second feeder PA impedance matching circuit 120. Thesecond feeder PA stage 122 is coupled between the second feeder PAimpedance matching circuit 120 and the second quadrature PA path 106.The second input PA impedance matching circuit 116 may provide at leastan approximate impedance match between the RF modulation circuitry 44(FIG. 5) and the second input PA stage 118. The second feeder PAimpedance matching circuit 120 may provide at least an approximateimpedance match between the second input PA stage 118 and the secondfeeder PA stage 122. In alternate embodiments of the secondnon-quadrature PA path 104, any or all of the second input PA impedancematching circuit 116, the second input PA stage 118, and the secondfeeder PA impedance matching circuit 120, may be omitted.

During the second PA operating mode, the second input PA impedancematching circuit 116 receives and forwards the second RF input signalSRFI to the second input PA stage 118. During the second PA operatingmode, the second input PA stage 118 receives and amplifies the forwardedsecond RF input signal SRFI to provide a second RF feeder input signalSFI to the second feeder PA stage 122 via the second feeder PA impedancematching circuit 120. During the second PA operating mode, the secondfeeder PA stage 122 receives and amplifies the second RF feeder inputsignal SFI to provide the second RF feeder output signal SFO via thesecond single-ended output SSO. The second feeder PA stage 122 may havea second output load line having a second load line slope. During thesecond PA operating mode, the envelope power supply signal EPS providespower for amplification to the second input PA stage 118 and to thesecond feeder PA stage 122. During the second PA operating mode, thesecond driver bias signal SDB provides biasing to the second input PAstage 118 and the second feeder PA stage 122.

FIG. 17 shows details of the first quadrature PA path 102 and the secondquadrature PA path 106 illustrated in FIG. 15 according to oneembodiment of the first quadrature PA path 102 and the second quadraturePA path 106. The first quadrature PA path 102 includes a firstquadrature RF splitter 124, a first in-phase amplification path 126, afirst quadrature-phase amplification path 128, and a first quadrature RFcombiner 130. The first quadrature RF splitter 124 has a firstsingle-ended input FSI, a first in-phase output FIO, and a firstquadrature-phase output FQO. The first quadrature RF combiner 130 has afirst in-phase input FII, a first quadrature-phase input FQI, and afirst quadrature combiner output FCO. The first single-ended output FSOis coupled to the first single-ended input FSI. In one embodiment of thefirst quadrature PA path 102, the first single-ended output FSO isdirectly coupled to the first single-ended input FSI. The first in-phaseamplification path 126 is coupled between the first in-phase output FIOand the first in-phase input FII. The first quadrature-phaseamplification path 128 is coupled between the first quadrature-phaseoutput FQO and the first quadrature-phase input FQI. The firstquadrature combiner output FCO is coupled to the antenna port AP (FIG.6) via the alpha switching circuitry 52 (FIG. 6) and the front-endaggregation circuitry 36 (FIG. 6).

During the first PA operating mode, the first quadrature RF splitter 124receives the first RF feeder output signal FFO via the firstsingle-ended input FSI. Further, during the first PA operating mode, thefirst quadrature RF splitter 124 splits and phase-shifts the first RFfeeder output signal FFO into a first in-phase RF input signal FIN and afirst quadrature-phase RF input signal FQN, such that the firstquadrature-phase RF input signal FQN is nominally phase-shifted from thefirst in-phase RF input signal FIN by about 90 degrees. The firstquadrature RF splitter 124 has a first input impedance presented at thefirst single-ended input FSI. In one embodiment of the first quadratureRF splitter 124, the first input impedance establishes the first loadline slope. During the first PA operating mode, the first in-phaseamplification path 126 receives and amplifies the first in-phase RFinput signal FIN to provide the first in-phase RF output signal FIT. Thefirst quadrature-phase amplification path 128 receives and amplifies thefirst quadrature-phase RF input signal FQN to provide the firstquadrature-phase RF output signal FQT.

During the first PA operating mode, the first quadrature RF combiner 130receives the first in-phase RF output signal FIT via the first in-phaseinput FII, and receives the first quadrature-phase RF output signal FQTvia the first quadrature-phase input FQI. Further, the first quadratureRF combiner 130 phase-shifts and combines the first in-phase RF outputsignal FIT and the first quadrature-phase RF output signal FQT toprovide the first RF output signal FRFO via the first quadraturecombiner output FCO, such that the phase-shifted first in-phase RFoutput signal FIT and first quadrature-phase RF output signal FQT areabout phase-aligned with one another before combining. During the firstPA operating mode, the envelope power supply signal EPS provides powerfor amplification to the first in-phase amplification path 126 and thefirst quadrature-phase amplification path 128. During the first PAoperating mode, the first final bias signal FFB provides biasing to thefirst in-phase amplification path 126 and the first quadrature-phaseamplification path 128.

The second quadrature PA path 106 includes a second quadrature RFsplitter 132, a second in-phase amplification path 134, a secondquadrature-phase amplification path 136, and a second quadrature RFcombiner 138. The second quadrature RF splitter 132 has a secondsingle-ended input SSI, a second in-phase output SIO, and a secondquadrature-phase output SQO. The second quadrature RF combiner 138 has asecond in-phase input SII, a second quadrature-phase input SQI, and asecond quadrature combiner output SCO. The second single-ended outputSSO is coupled to the second single-ended input SSI. In one embodimentof the second quadrature PA path 106, the second single-ended output SSOis directly coupled to the second single-ended input SSI. The secondin-phase amplification path 134 is coupled between the second in-phaseoutput SIO and the second in-phase input SII. The secondquadrature-phase amplification path 136 is coupled between the secondquadrature-phase output SQO and the second quadrature-phase input SQI.The second quadrature combiner output SCO is coupled to the antenna portAP (FIG. 6) via the alpha switching circuitry 52 (FIG. 6) and thefront-end aggregation circuitry 36 (FIG. 6).

During the second PA operating mode, the second quadrature RF splitter132 receives the second RF feeder output signal SFO via the secondsingle-ended input SSI. Further, during the second PA operating mode,the second quadrature RF splitter 132 splits and phase-shifts the secondRF feeder output signal SFO into a second in-phase RF input signal SINand a second quadrature-phase RF input signal SQN, such that the secondquadrature-phase RF input signal SQN is nominally phase-shifted from thesecond in-phase RF input signal SIN by about 90 degrees. The secondquadrature RF splitter 132 has a second input impedance presented at thesecond single-ended input SSI. In one embodiment of the secondquadrature RF splitter 132, the second input impedance establishes thesecond load line slope. During the second PA operating mode, the secondin-phase amplification path 134 receives and amplifies the secondin-phase RF input signal SIN to provide the second in-phase RF outputsignal SIT. The second quadrature-phase amplification path 136 receivesand amplifies the second quadrature-phase RF input signal SQN to providethe second quadrature-phase RF output signal SQT.

During the second PA operating mode, the second quadrature RF combiner138 receives the second in-phase RF output signal SIT via the secondin-phase input SII, and receives the second quadrature-phase RF outputsignal SQT via the second quadrature-phase input SQI. Further, thesecond quadrature RF combiner 138 phase-shifts and combines the secondin-phase RF output signal SIT and the second quadrature-phase RF outputsignal SQT to provide the second RF output signal SRFO via the secondquadrature combiner output SCO, such that the phase-shifted secondin-phase RF output signal SIT and second quadrature-phase RF outputsignal SQT are about phase-aligned with one another before combining.During the second PA operating mode, the envelope power supply signalEPS provides power for amplification to the second in-phaseamplification path 134 and the second quadrature-phase amplificationpath 136. During the second PA operating mode, the second final biassignal SFB provides biasing to the second in-phase amplification path134 and the second quadrature-phase amplification path 136.

In one embodiment of the RF PA circuitry 30 (FIG. 13), the secondtransmit path 48 (FIG. 13) is omitted. As such, the first feeder PAstage 114 (FIG. 16) is a feeder PA stage and the first single-endedoutput FSO (FIG. 16) is a single-ended output. The first RF feeder inputsignal FFI (FIG. 16) is an RF feeder input signal and the first RFfeeder output signal FFO (FIG. 16) is an RF feeder output signal. Thefeeder PA stage receives and amplifies the RF feeder input signal toprovide the RF feeder output signal via the single-ended output. Thefeeder PA stage has an output load line having a load line slope. Thefirst quadrature RF splitter 124 is a quadrature RF splitter and thefirst single-ended input FSI is a single-ended input. As such, thequadrature RF splitter has the single-ended input. In one embodiment ofthe first RF PA 50, the single-ended output is directly coupled to thesingle-ended input.

In the embodiment in which the second transmit path 48 (FIG. 13) isomitted, the first in-phase RF input signal FIN is an in-phase RF inputsignal and the first quadrature-phase RF input signal FQN is aquadrature-phase RF input signal. The quadrature RF splitter receivesthe RF feeder output signal via the single-ended input. Further, thequadrature RF splitter splits and phase-shifts the RF feeder outputsignal into the in-phase RF input signal and the quadrature-phase RFinput signal, such that the quadrature-phase RF input signal isnominally phase-shifted from the in-phase RF input signal by about 90degrees. The quadrature RF splitter has an input impedance presented atthe single-ended input. The input impedance substantially establishesthe load line slope. The first in-phase amplification path 126 is anin-phase amplification path and the first quadrature-phase amplificationpath 128 is a quadrature-phase amplification path. The first in-phase RFoutput signal FIT is an in-phase RF output signal and the firstquadrature-phase RF output signal FQT is a quadrature-phase RF outputsignal. As such, the in-phase amplification path receives and amplifiesthe in-phase RF input signal to provide the in-phase RF output signal.The quadrature-phase amplification path receives and amplifies thequadrature-phase RF input signal to provide the quadrature-phase RFoutput signal.

In the embodiment in which the second transmit path 48 (FIG. 13) isomitted, the first RF output signal FRFO is an RF output signal. Assuch, the quadrature RF combiner receives, phase-shifts, and combinesthe in-phase RF output signal and the quadrature-phase RF output signalto provide the RF output signal. In one embodiment of the quadrature RFsplitter, the input impedance has resistance and reactance, such thatthe reactance is less than the resistance. In a first exemplaryembodiment of the quadrature RF splitter, the resistance is greater thantwo times the reactance. In a second exemplary embodiment of thequadrature RF splitter, the resistance is greater than four times thereactance. In a third exemplary embodiment of the quadrature RFsplitter, the resistance is greater than six times the reactance. In afourth exemplary embodiment of the quadrature RF splitter, theresistance is greater than eight times the reactance. In a firstexemplary embodiment of the quadrature RF splitter, the resistance isgreater than ten times the reactance.

In alternate embodiments of the first quadrature PA path 102 and thesecond quadrature PA path 106, any or all of the first quadrature RFsplitter 124, the first quadrature RF combiner 130, the secondquadrature RF splitter 132, and the second quadrature RF combiner 138may be any combination of quadrature RF couplers, quadrature hybrid RFcouplers; Fisher couplers; lumped-element based RF couplers;transmission line based RF couplers; and combinations of phase-shiftingcircuitry and RF power couplers, such as phase-shifting circuitry andWilkinson couplers; and the like. As such, any of the RF couplers listedabove may be suitable to provide the first input impedance, the secondinput impedance, or both.

FIG. 18 shows details of the first in-phase amplification path 126, thefirst quadrature-phase amplification path 128, the second in-phaseamplification path 134, and the second quadrature-phase amplificationpath 136 illustrated in FIG. 17 according to one embodiment of the firstin-phase amplification path 126, the first quadrature-phaseamplification path 128, the second in-phase amplification path 134, andthe second quadrature-phase amplification path 136. The first in-phaseamplification path 126 includes a first in-phase driver PA impedancematching circuit 140, a first in-phase driver PA stage 142, a firstin-phase final PA impedance matching circuit 144, a first in-phase finalPA stage 146, and a first in-phase combiner impedance matching circuit148. The first in-phase driver PA impedance matching circuit 140 iscoupled between the first in-phase output FIO and the first in-phasedriver PA stage 142. The first in-phase final PA impedance matchingcircuit 144 is coupled between the first in-phase driver PA stage 142and the first in-phase final PA stage 146. The first in-phase combinerimpedance matching circuit 148 is coupled between the first in-phasefinal PA stage 146 and the first in-phase input FII.

The first in-phase driver PA impedance matching circuit 140 may provideat least an approximate impedance match between the first quadrature RFsplitter 124 and the first in-phase driver PA stage 142. The firstin-phase final PA impedance matching circuit 144 may provide at least anapproximate impedance match between the first in-phase driver PA stage142 and the first in-phase final PA stage 146. The first in-phasecombiner impedance matching circuit 148 may provide at least anapproximate impedance match between the first in-phase final PA stage146 and the first quadrature RF combiner 130.

During the first PA operating mode, the first in-phase driver PAimpedance matching circuit 140 receives and forwards the first in-phaseRF input signal FIN to the first in-phase driver PA stage 142, whichreceives and amplifies the forwarded first in-phase RF input signal toprovide an amplified first in-phase RF input signal to the firstin-phase final PA stage 146 via the first in-phase final PA impedancematching circuit 144. The first in-phase final PA stage 146 receives andamplifies the amplified first in-phase RF input signal to provide thefirst in-phase RF output signal FIT via the first in-phase combinerimpedance matching circuit 148. During the first PA operating mode, theenvelope power supply signal EPS provides power for amplification to thefirst in-phase driver PA stage 142 and the first in-phase final PA stage146. During the first PA operating mode, the first final bias signal FFBprovides biasing to the first in-phase driver PA stage 142 and the firstin-phase final PA stage 146.

The first quadrature-phase amplification path 128 includes a firstquadrature-phase driver PA impedance matching circuit 150, a firstquadrature-phase driver PA stage 152, a first quadrature-phase final PAimpedance matching circuit 154, a first quadrature-phase final PA stage156, and a first quadrature-phase combiner impedance matching circuit158. The first quadrature-phase driver PA impedance matching circuit 150is coupled between the first quadrature-phase output FQO and the firstquadrature-phase driver PA stage 152. The first quadrature-phase finalPA impedance matching circuit 154 is coupled between the firstquadrature-phase driver PA stage 152 and the first quadrature-phasefinal PA stage 156. The first quadrature-phase combiner impedancematching circuit 158 is coupled between the first quadrature-phase finalPA stage 156 and the first quadrature-phase input FQI.

The first quadrature-phase driver PA impedance matching circuit 150 mayprovide at least an approximate impedance match between the firstquadrature RF splitter 124 and the first quadrature-phase driver PAstage 152. The first quadrature-phase final PA impedance matchingcircuit 154 may provide at least an approximate impedance match betweenthe first quadrature-phase driver PA stage 152 and the firstquadrature-phase final PA stage 156. The first quadrature-phase combinerimpedance matching circuit 158 may provide at least an approximateimpedance match between the first quadrature-phase final PA stage 156and the first quadrature RF combiner 130.

During the first PA operating mode, the first quadrature-phase driver PAimpedance matching circuit 150 receives and forwards the firstquadrature-phase RF input signal FQN to the first quadrature-phasedriver PA stage 152, which receives and amplifies the forwarded firstquadrature-phase RF input signal to provide an amplified firstquadrature-phase RF input signal to the first quadrature-phase final PAstage 156 via the first quadrature-phase final PA impedance matchingcircuit 154. The first quadrature-phase final PA stage 156 receives andamplifies the amplified first quadrature-phase RF input signal toprovide the first quadrature-phase RF output signal FQT via the firstquadrature-phase combiner impedance matching circuit 158. During thefirst PA operating mode, the envelope power supply signal EPS providespower for amplification to the first quadrature-phase driver PA stage152 and the first quadrature-phase final PA stage 156. During the firstPA operating mode, the first final bias signal FFB provides biasing tothe first quadrature-phase driver PA stage 152 and the firstquadrature-phase final PA stage 156.

The second in-phase amplification path 134 includes a second in-phasedriver PA impedance matching circuit 160, a second in-phase driver PAstage 162, a second in-phase final PA impedance matching circuit 164, asecond in-phase final PA stage 166, and a second in-phase combinerimpedance matching circuit 168. The second in-phase driver PA impedancematching circuit 160 is coupled between the second in-phase output SIOand the second in-phase driver PA stage 162. The second in-phase finalPA impedance matching circuit 164 is coupled between the second in-phasedriver PA stage 162 and the second in-phase final PA stage 166. Thesecond in-phase combiner impedance matching circuit 168 is coupledbetween the second in-phase final PA stage 166 and the second in-phaseinput SII.

The second in-phase driver PA impedance matching circuit 160 may provideat least an approximate impedance match between the second quadrature RFsplitter 132 and the second in-phase driver PA stage 162. The secondin-phase final PA impedance matching circuit 164 may provide at least anapproximate impedance match between the second in-phase driver PA stage162 and the second in-phase final PA stage 166. The second in-phasecombiner impedance matching circuit 168 may provide at least anapproximate impedance match between the second in-phase final PA stage166 and the second quadrature RF combiner 138.

During the second PA operating mode, the second in-phase driver PAimpedance matching circuit 160 receives and forwards the second in-phaseRF input signal SIN to the second in-phase driver PA stage 162, whichreceives and amplifies the forwarded second in-phase RF input signal toprovide an amplified second in-phase RF input signal to the secondin-phase final PA stage 166 via the second in-phase final PA impedancematching circuit 164. The second in-phase final PA stage 166 receivesand amplifies the amplified second in-phase RF input signal to providethe second in-phase RF output signal SIT via the second in-phasecombiner impedance matching circuit 168. During the second PA operatingmode, the envelope power supply signal EPS provides power foramplification to the second in-phase driver PA stage 162 and the secondin-phase final PA stage 166. During the second PA operating mode, thesecond final bias signal SFB provides biasing to the second in-phasedriver PA stage 162 and the second in-phase final PA stage 166.

The second quadrature-phase amplification path 136 includes a secondquadrature-phase driver PA impedance matching circuit 170, a secondquadrature-phase driver PA stage 172, a second quadrature-phase final PAimpedance matching circuit 174, a second quadrature-phase final PA stage176, and a second quadrature-phase combiner impedance matching circuit178. The second quadrature-phase driver PA impedance matching circuit170 is coupled between the second quadrature-phase output SQO and thesecond quadrature-phase driver PA stage 172. The second quadrature-phasefinal PA impedance matching circuit 174 is coupled between the secondquadrature-phase driver PA stage 172 and the second quadrature-phasefinal PA stage 176. The second quadrature-phase combiner impedancematching circuit 178 is coupled between the second quadrature-phasefinal PA stage 176 and the second quadrature-phase input SQI.

The second quadrature-phase driver PA impedance matching circuit 170 mayprovide at least an approximate impedance match between the secondquadrature RF splitter 132 and the second quadrature-phase driver PAstage 172. The second quadrature-phase final PA impedance matchingcircuit 174 may provide at least an approximate impedance match betweenthe second quadrature-phase driver PA stage 172 and the secondquadrature-phase final PA stage 176. The second quadrature-phasecombiner impedance matching circuit 178 may provide at least anapproximate impedance match between the second quadrature-phase final PAstage 176 and the second quadrature RF combiner 138.

During the second PA operating mode, the second quadrature-phase driverPA impedance matching circuit 170 receives and forwards the secondquadrature-phase RF input signal SQN to the second quadrature-phasedriver PA stage 172, which receives and amplifies the forwarded secondquadrature-phase RF input signal to provide an amplified secondquadrature-phase RF input signal to the second quadrature-phase final PAstage 176 via the second quadrature-phase final PA impedance matchingcircuit 174. The second quadrature-phase final PA stage 176 receives andamplifies the amplified second quadrature-phase RF input signal toprovide the second quadrature-phase RF output signal SQT via the secondquadrature-phase combiner impedance matching circuit 178. During thesecond PA operating mode, the envelope power supply signal EPS providespower for amplification to the second quadrature-phase driver PA stage172 and the second quadrature-phase final PA stage 176. During thesecond PA operating mode, the second final bias signal SFB providesbiasing to the second quadrature-phase driver PA stage 172 and thesecond quadrature-phase final PA stage 176.

In alternate embodiments of the first in-phase amplification path 126,any or all of the first in-phase driver PA impedance matching circuit140, the first in-phase driver PA stage 142, the first in-phase final PAimpedance matching circuit 144, and the first in-phase combinerimpedance matching circuit 148 may be omitted. In alternate embodimentsof the first quadrature-phase amplification path 128, any or all of thefirst quadrature-phase driver PA impedance matching circuit 150, thefirst quadrature-phase driver PA stage 152, the first quadrature-phasefinal PA impedance matching circuit 154, and the first quadrature-phasecombiner impedance matching circuit 158 may be omitted. In alternateembodiments of the second in-phase amplification path 134, any or all ofthe second in-phase driver PA impedance matching circuit 160, the secondin-phase driver PA stage 162, the second in-phase final PA impedancematching circuit 164, and the second in-phase combiner impedancematching circuit 168 may be omitted. In alternate embodiments of thesecond quadrature-phase amplification path 136, any or all of the secondquadrature-phase driver PA impedance matching circuit 170, the secondquadrature-phase driver PA stage 172, the second quadrature-phase finalPA impedance matching circuit 174, and the second quadrature-phasecombiner impedance matching circuit 178 may be omitted.

FIG. 19 shows details of the first quadrature PA path 102 and the secondquadrature PA path 106 illustrated in FIG. 15 according to an alternateembodiment of the first quadrature PA path 102 and the second quadraturePA path 106. The first quadrature PA path 102 and the second quadraturePA path 106 illustrated in FIG. 19 are similar to the first quadraturePA path 102 and the second quadrature PA path 106 illustrated in FIG.17, except in the first quadrature PA path 102 and the second quadraturePA path 106 illustrated in FIG. 19, during the first PA operating mode,the first driver bias signal FDB provides further biasing to the firstin-phase amplification path 126 and the first quadrature-phaseamplification path 128, and during the second PA operating mode, thesecond driver bias signal SDB provides further biasing to the secondin-phase amplification path 134 and the second quadrature-phaseamplification path 136.

FIG. 20 shows details of the first in-phase amplification path 126, thefirst quadrature-phase amplification path 128, the second in-phaseamplification path 134, and the second quadrature-phase amplificationpath 136 illustrated in FIG. 19 according to an alternate embodiment ofthe first in-phase amplification path 126, the first quadrature-phaseamplification path 128, the second in-phase amplification path 134, andthe second quadrature-phase amplification path 136. The amplificationpaths 126, 128, 134, 136 illustrated in FIG. 20 are similar to theamplification paths 126, 128, 134, 136 illustrated in FIG. 18, except inthe amplification paths 126, 128, 134, 136 illustrated in FIG. 20,during the first PA operating mode, the first driver bias signal FDBprovides biasing to the first in-phase driver PA stage 142 and the firstquadrature-phase driver PA stage 152 instead of the first final biassignal FFB, and during the second PA operating mode, the second driverbias signal SDB provides biasing to the second in-phase driver PA stage162 and the second quadrature-phase driver PA stage 172 instead of thesecond final bias signal SFB.

FIG. 21 shows details of the first RF PA 50 and the second RF PA 54illustrated in FIG. 14 according an alternate embodiment of the first RFPA 50 and the second RF PA 54. The first RF PA 50 shown in FIG. 21 issimilar to the first RF PA 50 illustrated in FIG. 15. The second RF PA54 shown in FIG. 21 is similar to the second RF PA 54 illustrated inFIG. 15, except in the second RF PA 54 illustrated in FIG. 21 the secondquadrature PA path 106 is omitted. As such, during the second PAoperating mode, the second RF input signal SRFI provides the second RFfeeder output signal SFO to the second quadrature PA path 106. In thisregard, during the second PA operating mode, the second quadrature PApath 106 receives and amplifies the second RF input signal SRFI toprovide the second RF output signal SRFO. During the second PA operatingmode, the second quadrature PA path 106 receives the envelope powersupply signal EPS, which provides power for amplification. Further,during the second PA operating mode, the second quadrature PA path 106receives the second driver bias signal SDB and the second final biassignal SFB, both of which provide biasing to the second quadrature PApath 106.

FIG. 22 shows details of the first non-quadrature PA path 100, the firstquadrature PA path 102, and the second quadrature PA path 106illustrated in FIG. 21 according to an additional embodiment of thefirst non-quadrature PA path 100, the first quadrature PA path 102, andthe second quadrature PA path 106. The second quadrature PA path 106illustrated in FIG. 22 is similar to the second quadrature PA path 106illustrated in FIG. 20. The first quadrature PA path 102 illustrated inFIG. 22 is similar to the first quadrature PA path 102 illustrated inFIG. 20, except in the first quadrature PA path 102 illustrated in FIG.22, the first in-phase driver PA impedance matching circuit 140, thefirst in-phase driver PA stage 142, the first quadrature-phase driver PAimpedance matching circuit 150, and the first quadrature-phase driver PAstage 152 are omitted. In this regard, the first in-phase final PAimpedance matching circuit 144 is coupled between the first in-phaseoutput FIO and the first in-phase final PA stage 146. The first in-phasecombiner impedance matching circuit 148 is coupled between the firstin-phase final PA stage 146 and the first in-phase input FII. The firstin-phase final PA impedance matching circuit 144 may provide at least anapproximate impedance match between the first quadrature RF splitter 124and the first in-phase final PA stage 146. The first in-phase combinerimpedance matching circuit 148 may provide at least an approximateimpedance match between the first in-phase final PA stage 146 and thefirst quadrature RF combiner 130.

During the first PA operating mode, the first in-phase final PAimpedance matching circuit 144 receives and forwards the first in-phaseRF input signal FIN to the first in-phase final PA stage 146, whichreceives and amplifies the forwarded first in-phase RF input signal toprovide the first in-phase RF output signal FIT via the first in-phasecombiner impedance matching circuit 148. During the first PA operatingmode, the envelope power supply signal EPS provides power foramplification to the first in-phase final PA stage 146. During the firstPA operating mode, the first final bias signal FFB provides biasing tothe first in-phase final PA stage 146.

The first quadrature-phase final PA impedance matching circuit 154 iscoupled between the first quadrature-phase output FQO and the firstquadrature-phase final PA stage 156. The first quadrature-phase combinerimpedance matching circuit 158 is coupled between the firstquadrature-phase final PA stage 156 and the first quadrature-phase inputFQI. The first quadrature-phase final PA impedance matching circuit 154may provide at least an approximate impedance match between the firstquadrature RF splitter 124 and the first quadrature-phase final PA stage156. The first quadrature-phase combiner impedance matching circuit 158may provide at least an approximate impedance match between the firstquadrature-phase final PA stage 156 and the first quadrature RF combiner130.

During the first PA operating mode, the first quadrature-phase final PAimpedance matching circuit 154 receives and forwards the firstquadrature-phase RF input signal FQN to the first quadrature-phase finalPA stage 156, which receives and amplifies the forwarded firstquadrature-phase RF input signal to provide the first quadrature-phaseRF output signal FQT via the first quadrature-phase combiner impedancematching circuit 158. During the first PA operating mode, the envelopepower supply signal EPS provides power for amplification to the firstquadrature-phase final PA stage 156. During the first PA operating mode,the first final bias signal FFB provides biasing to the firstquadrature-phase final PA stage 156.

The first non-quadrature PA path 100 illustrated in FIG. 22 is similarto the first non-quadrature PA path 100 illustrated in FIG. 16, exceptin the first non-quadrature PA path 100 illustrated in FIG. 22, thefirst input PA impedance matching circuit 108 and the first input PAstage 110 are omitted. As such, the first feeder PA stage 114 is coupledbetween the first feeder PA impedance matching circuit 112 and the firstquadrature PA path 102. The first feeder PA impedance matching circuit112 may provide at least an approximate impedance match between the RFmodulation circuitry 44 (FIG. 5) and the first feeder PA stage 114.During the first PA operating mode, the first feeder PA impedancematching circuit 112 receives and forwards the first RF input signalFRFI to provide the first RF feeder input signal FFI to the first feederPA stage 114. During the first PA operating mode, the first feeder PAstage 114 receives and amplifies the first RF feeder input signal FFI toprovide the first RF feeder output signal FFO via the first single-endedoutput FSO. During the first PA operating mode, the envelope powersupply signal EPS provides power for amplification to the first feederPA stage 114. During the first PA operating mode, the first final biassignal FFB provides biasing to the first feeder PA stage 114.

In one embodiment of the first quadrature PA path 102, the firstquadrature PA path 102 has only one in-phase PA stage, which is thefirst in-phase final PA stage 146, and only one quadrature-phase PAstage, which is the first quadrature-phase final PA stage 156. In oneembodiment of the second quadrature PA path 106, the second in-phasedriver PA impedance matching circuit 160, the second in-phase driver PAstage 162, the second quadrature-phase driver PA impedance matchingcircuit 170, and the second quadrature-phase driver PA stage 172 areomitted. As such, the second quadrature PA path 106 has only onein-phase PA stage, which is the second in-phase final PA stage 166, andonly one quadrature-phase PA stage, which is the second quadrature-phasefinal PA stage 176.

FIG. 23 shows details of the first feeder PA stage 114 and the firstquadrature RF splitter 124 illustrated in FIG. 16 and FIG. 17,respectively, according to one embodiment of the first feeder PA stage114 and the first quadrature RF splitter 124. FIGS. 23 and 24 show onlya portion of the first feeder PA stage 114 and the first quadrature RFsplitter 124. The first feeder PA stage 114 includes a first outputtransistor element 180, an inverting output inductive element LIO, andthe first single-ended output FSO. The first output transistor element180 has a first transistor inverting output FTIO, a first transistornon-inverting output FTNO, and a first transistor input FTIN. The firsttransistor non-inverting output FTNO is coupled to a ground and thefirst transistor inverting output FTIO is coupled to the firstsingle-ended output FSO and to one end of the inverting output inductiveelement LIO. An opposite end of the inverting output inductive elementLIO receives the envelope power supply signal EPS.

The first quadrature RF splitter 124 has the first single-ended inputFSI, such that the first input impedance is presented at the firstsingle-ended input FSI. Since the first input impedance may bepredominantly resistive, the first input impedance may be approximatedas a first input resistive element RFI coupled between the firstsingle-ended input FSI and the ground. The first single-ended output FSOis directly coupled to the first single-ended input FSI. Therefore, thefirst input resistive element RFI is presented to the first transistorinverting output FTIO.

FIG. 24 shows details of the first feeder PA stage 114 and the firstquadrature RF splitter 124 illustrated in FIG. 16 and FIG. 17,respectively, according to an alternate embodiment of the first feederPA stage 114 and the first quadrature RF splitter 124. The first outputtransistor element 180 is an NPN bipolar transistor element, such thatan emitter of the NPN bipolar transistor element provides the firsttransistor non-inverting output FTNO (FIG. 23), a base of the NPNbipolar transistor element provides the first transistor input FTIN(FIG. 23), and a collector of the NPN bipolar transistor elementprovides the first transistor inverting output FTIO (FIG. 23). Theinverting output inductive element LIO has an inverting output inductorcurrent IDC, the collector of the NPN bipolar transistor element has acollector current IC, and the first input resistive element RFI has afirst input current IFR. The NPN bipolar transistor element has acollector-emitter voltage VCE between the emitter and the collector ofthe NPN bipolar transistor element.

In general, the first feeder PA stage 114 is the feeder PA stage havingthe single-ended output and an output transistor element, which has aninverting output. In general, the first quadrature RF splitter 124 isthe quadrature RF splitter having the single-ended input, such that theinput impedance is presented at the single-ended input. The invertingoutput may provide the single-ended output and may be directly coupledto the single-ended input. The inverting output may be a collector ofthe output transistor element and the output transistor element has theoutput load line.

FIG. 25 is a graph illustrating output characteristics of the firstoutput transistor element 180 illustrated in FIG. 24 according to oneembodiment of the first output transistor element 180. The horizontalaxis of the graph represents the collector-emitter voltage VCE of theNPN bipolar transistor element and the vertical axis represents thecollector current IC of the NPN bipolar transistor element.Characteristic curves 182 of the NPN bipolar transistor element areshown relating the collector-emitter voltage VCE to the collectorcurrent IC at different base currents (not shown). The NPN bipolartransistor element has a first output load line 184 having a first loadline slope 186. The first output load line 184 may be represented by anequation for a straight line having the form Y=mX+b, where X representsthe horizontal axis, Y represents the vertical axis, b represents theY-intercept, and m represents the first load line slope 186. As such,Y=IC, X=VCE, and b=ISAT, which is a saturation current ISAT of the NPNbipolar transistor element. Further, an X-intercept occurs at an offtransistor voltage VCO. Substituting into the equation for a straightline provides EQ. 1, as shown below.IC=m(VCE)+ISAT.  EQ. 1

EQ. 2 illustrates Ohm's Law as applied to the first input resistiveelement RFI, as shown below.VCE=(IFR)(RFI).  EQ. 2:

EQ. 3 illustrates Kirchhoff's Current Law applied to the circuitillustrated in FIG. 24 as shown below.IDC=IC+IFR.  EQ. 3

The inductive reactance of the inverting output inductive element LIO atfrequencies of interest may be large compared to the resistance of thefirst input resistive element RFI. As such, for the purpose of analysis,the inverting output inductor current IDC may be treated as a constantDC current. Therefore, when VCE=0, the voltage across the first inputresistive element RFI is zero, which makes IFR=0. From EQ. 3, if IFR=0,then IC=IDC. However, from EQ. 1, when VCE=0 and IC=IDC, then ISAT=IDC,which is a constant. Substituting into EQ. 1 provides EQ. 1A as shownbelow.IC=m(VCE)+IDC.  EQ. 1A

From FIG. 25, when IC=0, VCE=VCO. Substituting into EQ. 1A, EQ. 2, andEQ. 3 provides EQ. 1 B, EQ. 2A, and EQ. 3A as shown below.0=m(VCO)+IDC.  EQ. 1BVCO=(IFR)(RFI).  EQ. 2AIDC=0+IFR.  EQ. 3A

EQ. 3A may be substituted into EQ. 2A, which may be substituted into EQ.1B to provide EQ. 1C as shown below.0=m(VCO)+IDC=m(IDC)(RFI)+IDC.  EQ. 1C

Therefore, m=−1/RFI. As a result, the first load line slope 186, whichis represented by m is determined by the first input resistive elementRFI, such that there is a negative inverse relationship between thefirst load line slope 186 and the first input resistive element RFI. Ingeneral, the first load line slope 186 is based on the first inputimpedance, such that the first input impedance substantially establishesthe first load line slope 186. Further, there may be a negative inverserelationship between the first load line slope 186 and the first inputimpedance.

FIG. 26 illustrates a process for matching an input impedance, such asthe first input impedance to the first quadrature RF splitter 124 (FIG.16) to a target load line slope for a feeder PA stage, such as the firstfeeder PA stage 114 (FIG. 17). The first step of the process is todetermine an operating power range of an RF PA, which has the feeder PAstage feeding a quadrature RF splitter (Step A10). The next step of theprocess is to determine the target load line slope for the feeder PAstage based on the operating power range (Step A12). A further step isto determine the input impedance to the quadrature RF splitter thatsubstantially provides the target load line slope (Step A14). The finalstep of the process is to determine an operating frequency range of theRF PA, such that the target load line slope is further based on theoperating frequency range (Step A16). In an alternate embodiment of theprocess for matching the input impedance to the target load line slope,the final step (Step A16) is omitted.

FIG. 27 shows details of the first RF PA 50 illustrated in FIG. 14according an alternate embodiment of the first RF PA 50. The first RF PA50 illustrated in FIG. 27 is similar to the first RF PA 50 illustratedin FIG. 15, except the first RF PA 50 illustrated in FIG. 27 furtherincludes a first non-quadrature path power coupler 188. As previouslymentioned, the first quadrature PA path 102 may present a first inputimpedance at the first single-ended input FSI that is predominantlyresistive. Further, the first input impedance may be stable over a widefrequency range and over widely varying antenna loading conditions. As aresult, coupling RF power from the first single-ended output FSO may beused for RF power detection or sampling with a high degree of accuracyand directivity. Since the first single-ended input FSI may be directlycoupled to the first single-ended output FSO, coupling RF power from thefirst single-ended output FSO may be equivalent to coupling RF powerfrom the first single-ended input FSI.

The first non-quadrature path power coupler 188 is coupled to the firstsingle-ended output FSO and couples a portion of RF power flowing thoughthe first single-ended output FSO to provide a first non-quadrature pathpower output signal FNPO. In an additional embodiment of the first RF PA50, the first non-quadrature path power coupler 188 is coupled to thefirst single-ended input FSI and couples a portion of RF power flowingthough the first single-ended input FSI to provide the firstnon-quadrature path power output signal FNPO.

FIG. 28 shows details of the second RF PA 54 illustrated in FIG. 14according an alternate embodiment of the second RF PA 54. The second RFPA 54 illustrated in FIG. 28 is similar to the second RF PA 54illustrated in FIG. 15, except the second RF PA 54 illustrated in FIG.28 further includes a second non-quadrature path power coupler 190. Aspreviously mentioned, the second quadrature PA path 106 may present asecond input impedance at the second single-ended input SSI that ispredominantly resistive. Further, the second input impedance may bestable over a wide frequency range and over widely varying antennaloading conditions. As a result, coupling RF power from the secondsingle-ended output SSO may be used for RF power detection or samplingwith a high degree of accuracy and directivity. Since the secondsingle-ended input SSI may be directly coupled to the secondsingle-ended output SSO, coupling RF power from the second single-endedoutput SSO may be equivalent to coupling RF power from the secondsingle-ended input SSI.

The second non-quadrature path power coupler 190 is coupled to thesecond single-ended output SSO and couples a portion of RF power flowingthough the second single-ended output SSO to provide a secondnon-quadrature path power output signal SNPO. In an additionalembodiment of the second RF PA 54, the second non-quadrature path powercoupler 190 is coupled to the second single-ended input SSI and couplesa portion of RF power flowing though the second single-ended input SSIto provide the second non-quadrature path power output signal SNPO.

FIG. 29 shows details of the first in-phase amplification path 126, thefirst quadrature-phase amplification path 128, and the first quadratureRF combiner 130 illustrated in FIG. 22 according to one embodiment ofthe first in-phase amplification path 126, the first quadrature-phaseamplification path 128, and the first quadrature RF combiner 130. Thefirst in-phase combiner impedance matching circuit 148 and the firstquadrature-phase combiner impedance matching circuit 158 have beenomitted from the first in-phase amplification path 126 and the firstquadrature-phase amplification path 128, respectively. The firstquadrature RF combiner 130 includes first phase-shifting circuitry 192and a first Wilkinson RF combiner 194. The first phase-shiftingcircuitry 192 has the first in-phase input FII and the firstquadrature-phase input FQI. The first Wilkinson RF combiner 194 has thefirst quadrature combiner output FCO.

During the first PA operating mode, the first phase-shifting circuitry192 receives and phase-aligns RF signals from the first in-phase finalPA stage 146 and the first quadrature-phase final PA stage 156 via thefirst in-phase input FII and the first quadrature-phase input FQI,respectively, to provide phase-aligned RF signals to the first WilkinsonRF combiner 194. The first Wilkinson RF combiner 194 combinesphase-aligned RF signals to provide the first RF output signal FRFO viathe first quadrature combiner output FCO. The first phase-shiftingcircuitry 192 and the first Wilkinson RF combiner 194 may provide stableinput impedances presented at the first in-phase input FII and the firstquadrature-phase input FQI, respectively, which allows elimination ofthe first in-phase combiner impedance matching circuit 148 and the firstquadrature-phase combiner impedance matching circuit 158.

FIG. 30 shows details of the first feeder PA stage 114, the firstquadrature RF splitter 124, the first in-phase final PA impedancematching circuit 144, the first in-phase final PA stage 146, the firstquadrature-phase final PA impedance matching circuit 154, and the firstquadrature-phase final PA stage 156 illustrated in FIG. 29 according toone embodiment of the first feeder PA stage 114, the first quadrature RFsplitter 124, the first in-phase final PA impedance matching circuit144, the first in-phase final PA stage 146, the first quadrature-phasefinal PA impedance matching circuit 154, and the first quadrature-phasefinal PA stage 156. Further, FIG. 30 shows a portion of the firstphase-shifting circuitry 192 illustrated in FIG. 29.

The first in-phase final PA stage 146 includes a first in-phase finaltransistor element 196, first in-phase biasing circuitry 198, and afirst in-phase collector inductive element LCI. The firstquadrature-phase final PA stage 156 includes a first quadrature-phasefinal transistor element 200, first quadrature-phase biasing circuitry202, and a first quadrature-phase collector inductive element LCQ. Thefirst in-phase final PA impedance matching circuit 144 includes a firstin-phase series capacitive element CSI1, a second in-phase seriescapacitive element CSI2, and a first in-phase shunt inductive elementLUI. The first quadrature-phase final PA impedance matching circuit 154includes a first quadrature-phase series capacitive element CSQ1, asecond quadrature-phase series capacitive element CSQ2, and a firstquadrature-phase shunt inductive element LUQ.

The first quadrature RF splitter 124 includes a first pair 204 oftightly coupled inductors and a first isolation port resistive elementRI1. The first pair 204 of tightly coupled inductors has first parasiticcapacitance 206 between the first pair 204 of tightly coupled inductors.Additionally, the first quadrature RF splitter 124 has the firstsingle-ended input FSI, the first in-phase output FIO, and the firstquadrature-phase output FQO. The first feeder PA stage 114 includes thefirst output transistor element 180, first feeder biasing circuitry 208,a first DC blocking capacitive element CD1, a first base resistiveelement RB1, and a first collector inductive element LC1. Additionally,the first feeder PA stage 114 has the first single-ended output FSO.

The first output transistor element 180 shown is an NPN bipolartransistor element. Other embodiments of the first output transistorelement 180 may use other types of transistor elements, such as fieldeffect transistor elements (FET) elements. The first DC blockingcapacitive element CD1 is coupled between the first feeder PA impedancematching circuit 112 (FIG. 22) and the first base resistive element RB.A base of the first output transistor element 180 and the first feederbiasing circuitry 208 are coupled to the first base resistive elementRB1. In alternate embodiments of the first feeder PA stage 114, thefirst base resistive element RB1, the first DC blocking capacitiveelement CD1, or both may be omitted. The first feeder biasing circuitry208 receives the first driver bias signal FDB. An emitter of the firstoutput transistor element 180 is coupled to a ground. A collector of thefirst output transistor element 180 is coupled to the first single-endedoutput FSO. One end of the first collector inductive element LC1 iscoupled to the first single-ended output FSO. An opposite end of thefirst collector inductive element LC1 receives the envelope power supplysignal EPS. The first single-ended output FSO is coupled to the firstsingle-ended input FSI.

During the first PA operating mode, the first output transistor element180 receives and amplifies an RF signal from the first feeder PAimpedance matching circuit 112 (FIG. 22) via the first DC blockingcapacitive element CD1 and the first base resistive element RB1 toprovide the first RF feeder output signal FFO (FIG. 29) to the firstsingle-ended input FSI via the first single-ended output FSO. Theenvelope power supply signal EPS provides power for amplification viathe first collector inductive element LC1. The first feeder biasingcircuitry 208 biases the first output transistor element 180. The firstdriver bias signal FDB provides power for biasing the first outputtransistor element 180 to the first feeder biasing circuitry 208.

The first quadrature RF splitter 124 illustrated in FIG. 30 is aquadrature hybrid coupler. In this regard, the first pair 204 of tightlycoupled inductors, the first parasitic capacitance 206, and the firstisolation port resistive element RI1 provide quadrature hybrid couplerfunctionality. As such, the first single-ended input FSI functions as aninput port to the quadrature hybrid coupler, the first in-phase outputFIO functions as a zero degree output port from the quadrature hybridcoupler, and the first quadrature-phase output FQO functions as a 90degree output port from the quadrature hybrid coupler. One of the firstpair 204 of tightly coupled inductors is coupled between the firstsingle-ended input FSI and the first in-phase output F10. Another of thefirst pair 204 of tightly coupled inductors has a first end coupled tothe first quadrature-phase output FQO and a second end coupled to thefirst isolation port resistive element RI1. As such, the second endfunctions as an isolation port of the quadrature hybrid coupler. In thisregard, the first isolation port resistive element RI1 is coupledbetween the isolation port and the ground. The first in-phase output FIOis coupled to the first in-phase series capacitive element CSI1 and thefirst quadrature-phase output FQO is coupled to the firstquadrature-phase series capacitive element CSQ1.

During the first PA operating mode, the first pair 204 of tightlycoupled inductors receives, splits, and phase-shifts the first RF feederoutput signal FFO (FIG. 29) from the first single-ended output FSO viathe first single-ended input FSI to provide split, phase-shifted outputsignals to the first in-phase series capacitive element CSI1 and thefirst quadrature-phase series capacitive element CSQ1. As previouslymentioned, the first input impedance is presented at the firstsingle-ended input FSI. As such, the first input impedance issubstantially based on the first parasitic capacitance 206 andinductances of the first pair 204 of tightly coupled inductors.

The first in-phase series capacitive element CSI1 and the secondin-phase series capacitive element CSI2 are coupled in series betweenthe first in-phase output FIO and a base of the first in-phase finaltransistor element 196. The first in-phase shunt inductive element LUIis coupled between the ground and a junction between the first in-phaseseries capacitive element CSI1 and the second in-phase series capacitiveelement CSI2. The first quadrature-phase series capacitive element CSQ1and the second quadrature-phase series capacitive element CSQ2 arecoupled in series between the first quadrature-phase output FQO and abase of the first quadrature-phase final transistor element 200. Thefirst quadrature-phase shunt inductive element LUQ is coupled betweenthe ground and a junction between the first quadrature-phase seriescapacitive element CSQ1 and the second quadrature-phase seriescapacitive element CSQ2.

The first in-phase series capacitive element CSI1, the second in-phaseseries capacitive element CSI2, and the first in-phase shunt inductiveelement LUI form a “T” network, which may provide at least anapproximate impedance match between the first in-phase output FIO andthe base of the first in-phase final transistor element 196. Similarly,the first quadrature-phase series capacitive element CSQ1, the secondquadrature-phase series capacitive element CSQ2, and the firstquadrature-phase shunt inductive element LUQ form a “T” network, whichmay provide at least an approximate impedance match between the firstquadrature-phase output FQO and the base of the first quadrature-phasefinal transistor element 200.

During the first PA operating mode, the first in-phase final PAimpedance matching circuit 144 receives and forwards an RF signal fromthe first in-phase output FIO to the base of the first in-phase finaltransistor element 196 via the first in-phase series capacitive elementCSI1 and the second in-phase series capacitive element CSI2. During thefirst PA operating mode, the first quadrature-phase final PA impedancematching circuit 154 receives and forwards an RF signal from the firstquadrature-phase output FQO to the base of the first quadrature-phasefinal transistor element 200 via the first quadrature-phase seriescapacitive element CSQ1 and the second quadrature-phase seriescapacitive element CSQ2.

The first in-phase final transistor element 196 shown is an NPN bipolartransistor element. Other embodiments of the first in-phase finaltransistor element 196 may use other types of transistor elements, suchas FET elements. The base of the first in-phase final transistor element196 and the first in-phase biasing circuitry 198 are coupled to thesecond in-phase series capacitive element CSI2. The first in-phasebiasing circuitry 198 receives the first final bias signal FFB. Anemitter of the first in-phase final transistor element 196 is coupled tothe ground. A collector of the first in-phase final transistor element196 is coupled to the first in-phase input FII. One end of the firstin-phase collector inductive element LCI is coupled to the collector ofthe first in-phase final transistor element 196. An opposite end of thefirst in-phase collector inductive element LCI receives the envelopepower supply signal EPS.

During the first PA operating mode, the first in-phase final transistorelement 196 receives and amplifies an RF signal from the second in-phaseseries capacitive element CSI2 to provide an RF output signal to thefirst in-phase input FII. The envelope power supply signal EPS providespower for amplification via the first in-phase collector inductiveelement LCI. The first in-phase biasing circuitry 198 biases the firstin-phase final transistor element 196. The first final bias signal FFBprovides power for biasing the first in-phase final transistor element196 to the first in-phase biasing circuitry 198.

The first quadrature-phase final transistor element 200 shown is an NPNbipolar transistor element. Other embodiments of the firstquadrature-phase final transistor element 200 may use other types oftransistor elements, such as FET elements. The base of the firstquadrature-phase final transistor element 200 and the firstquadrature-phase biasing circuitry 202 are coupled to the secondquadrature-phase series capacitive element CSQ2. The firstquadrature-phase biasing circuitry 202 receives the first final biassignal FFB. An emitter of the first quadrature-phase final transistorelement 200 is coupled to the ground. A collector of the firstquadrature-phase final transistor element 200 is coupled to the firstquadrature-phase input FQI. One end of the first quadrature-phasecollector inductive element LCQ is coupled to the collector of the firstquadrature-phase final transistor element 200. An opposite end of thefirst quadrature-phase collector inductive element LCQ receives theenvelope power supply signal EPS.

During the first PA operating mode, the first quadrature-phase finaltransistor element 200 receives and amplifies an RF signal from thesecond quadrature-phase series capacitive element CSQ2 to provide an RFoutput signal to the first quadrature-phase input FQI. The envelopepower supply signal EPS provides power for amplification via the firstquadrature-phase collector inductive element LCQ. The firstquadrature-phase biasing circuitry 202 biases the first quadrature-phasefinal transistor element 200. The first final bias signal FFB providespower for biasing the first quadrature-phase final transistor element200 to the first quadrature-phase biasing circuitry 202.

In one embodiment of the RF PA circuitry 30 (FIG. 5), the RF PAcircuitry 30 includes a first PA semiconductor die 210. In oneembodiment of the first PA semiconductor die 210, the first PAsemiconductor die 210 includes the first output transistor element 180,the first in-phase final transistor element 196, the first in-phasebiasing circuitry 198, the first quadrature-phase final transistorelement 200, the first quadrature-phase biasing circuitry 202, the firstpair 204 of tightly coupled inductors, the first feeder biasingcircuitry 208, the first in-phase series capacitive element CSI1, thesecond in-phase series capacitive element CSI2, the firstquadrature-phase series capacitive element CSQ1, the secondquadrature-phase series capacitive element CSQ2, the first isolationport resistive element RI1, the first base resistive element RB1, andthe first DC blocking capacitive element CD1.

In alternate embodiments of the first PA semiconductor die 210, thefirst PA semiconductor die 210 may not include any or all of the firstoutput transistor element 180, the first in-phase final transistorelement 196, the first in-phase biasing circuitry 198, the firstquadrature-phase final transistor element 200, the firstquadrature-phase biasing circuitry 202, the first pair 204 of tightlycoupled inductors, the first feeder biasing circuitry 208, the firstin-phase series capacitive element CSI1, the second in-phase seriescapacitive element CSI2, the first quadrature-phase series capacitiveelement CSQ1, the second quadrature-phase series capacitive elementCSQ2, the first isolation port resistive element RI1, the first baseresistive element RB1, and the first DC blocking capacitive element CD1.

FIG. 31 shows details of the first feeder PA stage 114, the firstquadrature RF splitter 124, the first in-phase final PA impedancematching circuit 144, the first in-phase final PA stage 146, the firstquadrature-phase final PA impedance matching circuit 154, and the firstquadrature-phase final PA stage 156 illustrated in FIG. 29 according toan alternate embodiment of the first feeder PA stage 114, the firstquadrature RF splitter 124, the first in-phase final PA impedancematching circuit 144, the first in-phase final PA stage 146, the firstquadrature-phase final PA impedance matching circuit 154, and the firstquadrature-phase final PA stage 156. Further, FIG. 31 shows a portion ofthe first phase-shifting circuitry 192 illustrated in FIG. 29.

The first feeder PA stage 114, the first in-phase final PA impedancematching circuit 144, the first in-phase final PA stage 146, the firstquadrature-phase final PA impedance matching circuit 154, and the firstquadrature-phase final PA stage 156 illustrated in FIG. 31 are similarto the first feeder PA stage 114, the first in-phase final PA impedancematching circuit 144, the first in-phase final PA stage 146, the firstquadrature-phase final PA impedance matching circuit 154, and the firstquadrature-phase final PA stage 156 illustrated in FIG. 30. The firstquadrature RF splitter 124 illustrated in FIG. 31 is similar to thefirst quadrature RF splitter 124 illustrated in FIG. 30, except thefirst quadrature RF splitter 124 illustrated in FIG. 31 further includesa first coupler capacitive element CC1 coupled between the first pair204 of tightly coupled inductors and a second coupler capacitive elementCC2 coupled between the first pair 204 of tightly coupled inductors.Specifically, the first coupler capacitive element CC1 is coupledbetween the first in-phase output FIO and the first isolation portresistive element RI1. The second coupler capacitive element CC2 iscoupled between the first single-ended input FSI and the firstquadrature-phase output FQO.

The first input impedance is substantially based on the first parasiticcapacitance 206, inductances of the first pair 204 of tightly coupledinductors, the first coupler capacitive element CC1, and the secondcoupler capacitive element CC2. In general, the first input impedance isbased on the first parasitic capacitance 206 and inductances of thefirst pair 204 of tightly coupled inductors. The first input impedanceis further based on at least one coupler capacitive element, such as thefirst coupler capacitive element CC1, the second coupler capacitiveelement CC2, or both, coupled between the first pair 204 of tightlycoupled inductors. In an alternate embodiment of the first quadrature RFsplitter 124, either the first coupler capacitive element CCI or thesecond coupler capacitive element CC2 is omitted.

FIG. 32 shows details of the first phase-shifting circuitry 192 and thefirst Wilkinson RF combiner 194 illustrated in FIG. 29 according to oneembodiment of the first phase-shifting circuitry 192 and the firstWilkinson RF combiner 194. The first phase-shifting circuitry 192includes a first in-phase phase-shift capacitive element CPI1, a firstquadrature-phase phase-shift capacitive element CPQ1, a first in-phasephase-shift inductive element LPI1, and a first quadrature-phasephase-shift inductive element LPQ1. The first Wilkinson RF combiner 194includes a first Wilkinson resistive element RW1, a first Wilkinsoncapacitive element CW1, a first Wilkinson in-phase side capacitiveelement CWI1, a first Wilkinson quadrature-phase side capacitive elementCWQ1, a first Wilkinson in-phase side inductive element LWI1, a firstWilkinson quadrature-phase side inductive element LWQ1, a second DCblocking capacitive element CD2, a third DC blocking capacitive elementCD3, and a fourth DC blocking capacitive element CD4

The first in-phase phase-shift capacitive element CPI1 is coupledbetween the first in-phase input FII and a first internal node (notshown). The first in-phase phase-shift inductive element LPI1 is coupledbetween the first internal node and the ground. The firstquadrature-phase phase-shift inductive element LPQ1 is coupled betweenthe first quadrature-phase input FQI and a second internal node (notshown). The first quadrature-phase phase-shift capacitive element CPQ1is coupled between the second internal node and the ground. The secondDC blocking capacitive element CD2 and the first Wilkinson resistiveelement RW1 are coupled in series between the first internal node andthe second internal node. The first Wilkinson in-phase side capacitiveelement CWI1 is coupled between the first internal node and the ground.The first Wilkinson quadrature-phase side capacitive element CWQ1 iscoupled between the first internal node and the ground. The firstWilkinson in-phase side inductive element LWI1 is coupled in series withthe third DC blocking capacitive element CD3 between the first internalnode and the first quadrature combiner output FCO. The first Wilkinsonquadrature-phase side inductive element LWQ1 is coupled in series withthe fourth DC blocking capacitive element CD4 between the secondinternal node and the first quadrature combiner output FCO. The firstWilkinson capacitive element CW1 is coupled between the first quadraturecombiner output FCO and the ground.

FIG. 33 shows details of the second non-quadrature PA path 104illustrated in FIG. 16 and details of the second quadrature PA path 106illustrated in FIG. 18 according to one embodiment of the secondnon-quadrature PA path 104 and the second quadrature PA path 106.Further, FIG. 33 shows details of the second quadrature RF combiner 138illustrated in FIG. 18 according to one embodiment of the secondquadrature RF combiner 138 illustrated in FIG. 18. The second input PAimpedance matching circuit 116, the second input PA stage 118, thesecond in-phase driver PA impedance matching circuit 160, the secondin-phase driver PA stage 162, the second in-phase combiner impedancematching circuit 168, the second quadrature-phase driver PA impedancematching circuit 170, the second quadrature-phase driver PA stage 172,and the second quadrature-phase combiner impedance matching circuit 178have been omitted from the second non-quadrature PA path 104 and thesecond quadrature PA path 106.

The second quadrature RF combiner 138 includes second phase-shiftingcircuitry 212 and a second Wilkinson RF combiner 214. The secondphase-shifting circuitry 212 has the second in-phase input SII and thesecond quadrature-phase input SQI, and the second Wilkinson RF combiner214 has the second quadrature combiner output SCO.

During the second PA operating mode, the second phase-shifting circuitry212 receives and phase-aligns RF signals from the second in-phase finalPA stage 166 and the second quadrature-phase final PA stage 176 via thesecond in-phase input SII and the second quadrature-phase input SQI,respectively, to provide phase-aligned RF signals to the secondWilkinson RF combiner 214. The second Wilkinson RF combiner 214 combinesphase-aligned RF signals to provide the second RF output signal SRFO viathe second quadrature combiner output SCO. The second phase-shiftingcircuitry 212 and the second Wilkinson RF combiner 214 may providestable input impedances presented at the second in-phase input SII andthe second quadrature-phase input SQI, respectively, which allowselimination of the second in-phase combiner impedance matching circuit168 and the second quadrature-phase combiner impedance matching circuit178.

FIG. 34 shows details of the second feeder PA stage 122, the secondquadrature RF splitter 132, the second in-phase final PA impedancematching circuit 164, the second in-phase final PA stage 166, the secondquadrature-phase final PA impedance matching circuit 174, and the secondquadrature-phase final PA stage 176 illustrated in FIG. 33 according toone embodiment of the second feeder PA stage 122, the second quadratureRF splitter 132, the second in-phase final PA impedance matching circuit164, the second in-phase final PA stage 166, the second quadrature-phasefinal PA impedance matching circuit 174, and the second quadrature-phasefinal PA stage 176. Further, FIG. 34 shows a portion of the secondphase-shifting circuitry 212 illustrated in FIG. 33.

The second in-phase final PA stage 166 includes a second in-phase finaltransistor element 216, second in-phase biasing circuitry 218, and asecond in-phase collector inductive element LLI. The secondquadrature-phase final PA stage 176 includes a second quadrature-phasefinal transistor element 220, a second quadrature-phase biasingcircuitry 222, and a second quadrature-phase collector inductive elementLLQ. The second in-phase final PA impedance matching circuit 164includes a third in-phase series capacitive element CSI3, a fourthin-phase series capacitive element CSI4, and a second in-phase shuntinductive element LNI. The second quadrature-phase final PA impedancematching circuit 174 includes a third quadrature-phase series capacitiveelement CSQ3, a fourth quadrature-phase series capacitive element CSQ4,and a second quadrature-phase shunt inductive element LNQ.

The second quadrature RF splitter 132 includes a second pair 224 oftightly coupled inductors and a second isolation port resistive elementRI2. The second pair 224 of tightly coupled inductors has secondparasitic capacitance 226 between the second pair 224 of tightly coupledinductors. Additionally, the second quadrature RF splitter 132 has thesecond single-ended input SSI, the second in-phase output SIO, and thesecond quadrature-phase output SQO. The second feeder PA stage 122includes a second output transistor element 228, second feeder biasingcircuitry 230, a fifth DC blocking capacitive element CD5, a second baseresistive element RB2, and a second collector inductive element LC2.Additionally, the second feeder PA stage 122 has the second single-endedoutput SSO.

The second output transistor element 228 shown is an NPN bipolartransistor element. Other embodiments of the second output transistorelement 228 may use other types of transistor elements, such as fieldeffect transistor elements (FET) elements. The fifth DC blockingcapacitive element CD5 is coupled between the second feeder PA impedancematching circuit 120 (FIG. 33) and the second base resistive elementRB2. A base of the second output transistor element 228 and the secondfeeder biasing circuitry 230 are coupled to the second base resistiveelement RB2. In alternate embodiments of the second feeder PA stage 122,the second base resistive element RB2, the fifth DC blocking capacitiveelement CD5, or both may be omitted. The second feeder biasing circuitry230 receives the second driver bias signal SDB. An emitter of the secondoutput transistor element 228 is coupled to a ground. A collector of thesecond output transistor element 228 is coupled to the secondsingle-ended output SSO. One end of the second collector inductiveelement LC2 is coupled to the second single-ended output SSO. Anopposite end of the second collector inductive element LC2 receives theenvelope power supply signal EPS. The second single-ended output SSO iscoupled to the second single-ended input SSI.

During the second PA operating mode, the second output transistorelement 228 receives and amplifies an RF signal from the second feederPA impedance matching circuit 120 (FIG. 33) via the fifth DC blockingcapacitive element CD5 and the second base resistive element RB2 toprovide the second RF feeder output signal SFO (FIG. 33) to the secondsingle-ended input SSI via the second single-ended output SSO. Theenvelope power supply signal EPS provides power for amplification viathe second collector inductive element LC2. The second feeder biasingcircuitry 230 biases the second output transistor element 228. Thesecond driver bias signal SDB provides power for biasing the secondoutput transistor element 228 to the second feeder biasing circuitry230.

The second quadrature RF splitter 132 illustrated in FIG. 34 is aquadrature hybrid coupler. In this regard, the second pair 224 oftightly coupled inductors, the second parasitic capacitance 226, and thesecond isolation port resistive element RI2 provide quadrature hybridcoupler functionality. As such, the second single-ended input SSIfunctions as an input port to the quadrature hybrid coupler, the secondin-phase output SIO functions as a zero degree output port from thequadrature hybrid coupler, and the second quadrature-phase output SQOfunctions as a 90 degree output port from the quadrature hybrid coupler.One of the second pair 224 of tightly coupled inductors is coupledbetween the second single-ended input SSI and the second in-phase outputSIO. Another of the second pair 224 of tightly coupled inductors has afirst end coupled to the second quadrature-phase output SQO and a secondend coupled to the second isolation port resistive element RI2. As such,the second end functions as an isolation port of the quadrature hybridcoupler. In this regard, the second isolation port resistive element RI2is coupled between the isolation port and the ground. The secondin-phase output SIO is coupled to the third in-phase series capacitiveelement CSI3 and the second quadrature-phase output SQO is coupled tothe third quadrature-phase series capacitive element CSQ3.

During the second PA operating mode, the second pair 224 of tightlycoupled inductors receives, splits, and phase-shifts the second RFfeeder output signal SFO (FIG. 33) from the second single-ended outputSSO via the second single-ended input SSI to provide split,phase-shifted output signals to the third in-phase series capacitiveelement CSI3 and the third quadrature-phase series capacitive elementCSQ3. As previously mentioned, the second input impedance is presentedat the second single-ended input SSI. As such, the second inputimpedance is substantially based on the second parasitic capacitance 226and inductances of the second pair 224 of tightly coupled inductors.

The third in-phase series capacitive element CSI3 and the fourthin-phase series capacitive element CSI4 are coupled in series betweenthe second in-phase output SIO and a base of the second in-phase finaltransistor element 216. The second in-phase shunt inductive element LNIis coupled between the ground and a junction between the third in-phaseseries capacitive element CSI3 and the fourth in-phase series capacitiveelement CSI4. The third quadrature-phase series capacitive element CSQ3and the fourth quadrature-phase series capacitive element CSQ4 arecoupled in series between the second quadrature-phase output SQO and abase of the second quadrature-phase final transistor element 220. Thesecond quadrature-phase shunt inductive element LNQ is coupled betweenthe ground and a junction between the third quadrature-phase seriescapacitive element CSQ3 and the fourth quadrature-phase seriescapacitive element CSQ4.

The third in-phase series capacitive element CSI3, the fourth in-phaseseries capacitive element CSI4, and the second in-phase shunt inductiveelement LNI form a “T” network, which may provide at least anapproximate impedance match between the second in-phase output SIO andthe base of the second in-phase final transistor element 216. Similarly,the third quadrature-phase series capacitive element CSQ3, the fourthquadrature-phase series capacitive element CSQ4, and the secondquadrature-phase shunt inductive element LNQ form a “T” network, whichmay provide at least an approximate impedance match between the secondquadrature-phase output SQO and the base of the second quadrature-phasefinal transistor element 220.

During the second PA operating mode, the second in-phase final PAimpedance matching circuit 164 receives and forwards an RF signal fromthe second in-phase output SIO to the base of the second in-phase finaltransistor element 216 via the third in-phase series capacitive elementCSI3 and the fourth in-phase series capacitive element CSI4. During thesecond PA operating mode, the second quadrature-phase final PA impedancematching circuit 174 receives and forwards an RF signal from the secondquadrature-phase output SQO to the base of the second quadrature-phasefinal transistor element 220 via the third quadrature-phase seriescapacitive element CSQ3 and the fourth quadrature-phase seriescapacitive element CSQ4. The second in-phase final transistor element216 shown is an NPN bipolar transistor element. Other embodiments of thesecond in-phase final transistor element 216 may use other types oftransistor elements, such as FET elements. The base of the secondin-phase final transistor element 216 and the second in-phase biasingcircuitry 218 are coupled to the fourth in-phase series capacitiveelement CSI4.

The second in-phase biasing circuitry 218 receives the second final biassignal SFB. An emitter of the second in-phase final transistor element216 is coupled to the ground. A collector of the second in-phase finaltransistor element 216 is coupled to the second in-phase input SII. Oneend of the second in-phase collector inductive element LLI is coupled tothe collector of the second in-phase final transistor element 216. Anopposite end of the second in-phase collector inductive element LLIreceives the envelope power supply signal EPS.

During the second PA operating mode, the second in-phase finaltransistor element 216 receives and amplifies an RF signal from thefourth in-phase series capacitive element CSI4 to provide an RF outputsignal to the second in-phase input SII. The envelope power supplysignal EPS provides power for amplification via the second in-phasecollector inductive element LLI. The second in-phase biasing circuitry218 biases the second in-phase final transistor element 216. The secondfinal bias signal SFB provides power for biasing the second in-phasefinal transistor element 216 to the second in-phase biasing circuitry218.

The second quadrature-phase final transistor element 220 shown is an NPNbipolar transistor element. Other embodiments of the secondquadrature-phase final transistor element 220 may use other types oftransistor elements, such as FET elements. The base of the secondquadrature-phase final transistor element 220 and the secondquadrature-phase biasing circuitry 222 are coupled to the fourthquadrature-phase series capacitive element CSQ4. The secondquadrature-phase biasing circuitry 222 receives the second final biassignal SFB. An emitter of the second quadrature-phase final transistorelement 220 is coupled to the ground. A collector of the secondquadrature-phase final transistor element 220 is coupled to the secondquadrature-phase input SQI. One end of the second quadrature-phasecollector inductive element LLQ is coupled to the collector of thesecond quadrature-phase final transistor element 220. An opposite end ofthe second quadrature-phase collector inductive element LLQ receives theenvelope power supply signal EPS.

During the second PA operating mode, the second quadrature-phase finaltransistor element 220 receives and amplifies an RF signal from thefourth quadrature-phase series capacitive element CSQ4 to provide an RFoutput signal to the second quadrature-phase input SQI. The envelopepower supply signal EPS provides power for amplification via the secondquadrature-phase collector inductive element LLQ. The secondquadrature-phase biasing circuitry 222 biases the secondquadrature-phase final transistor element 220. The second final biassignal SFB provides power for biasing the second quadrature-phase finaltransistor element 220 to the second quadrature-phase biasing circuitry222.

In one embodiment of the RF PA circuitry 30 (FIG. 5), the RF PAcircuitry 30 includes a second PA semiconductor die 232. In oneembodiment of the second PA semiconductor die 232, the second PAsemiconductor die 232 includes the second output transistor element 228,second in-phase final transistor element 216, second in-phase biasingcircuitry 218, the second quadrature-phase final transistor element 220,second quadrature-phase biasing circuitry 222, the second pair 224 oftightly coupled inductors, the second feeder biasing circuitry 230, thethird in-phase series capacitive element CSI3, the fourth in-phaseseries capacitive element CSI4, the third quadrature-phase seriescapacitive element CSQ3, the fourth quadrature-phase series capacitiveelement CSQ4, the second isolation port resistive element RI2, thesecond base resistive element RB2, and the fifth DC blocking capacitiveelement CD5.

In alternate embodiments of the second PA semiconductor die 232, thesecond PA semiconductor die 232 may not include any or all of the secondoutput transistor element 228, the second in-phase final transistorelement 216, the second in-phase biasing circuitry 218, the secondquadrature-phase final transistor element 220, the secondquadrature-phase biasing circuitry 222, the second pair 224 of tightlycoupled inductors, the second feeder biasing circuitry 230, the thirdin-phase series capacitive element CSI3, the fourth in-phase seriescapacitive element CSI4, the third quadrature-phase series capacitiveelement CSQ3, the fourth quadrature-phase series capacitive elementCSQ4, the second isolation port resistive element RI2, the second baseresistive element RB2, and the fifth DC blocking capacitive element CD5.

FIG. 35 shows details of the second phase-shifting circuitry 212 and thesecond Wilkinson RF combiner 214 illustrated in FIG. 33 according to oneembodiment of the second phase-shifting circuitry 212 and the secondWilkinson RF combiner 214. The second phase-shifting circuitry 212includes a second in-phase phase-shift capacitive element CPI2, a secondquadrature-phase phase-shift capacitive element CPQ2, a second in-phasephase-shift inductive element LPI2, and a second quadrature-phasephase-shift inductive element LPQ2. The second Wilkinson RF combiner 214includes a second Wilkinson resistive element RW2, a second Wilkinsoncapacitive element CW2, a second Wilkinson in-phase side capacitiveelement CWI2, a second Wilkinson quadrature-phase side capacitiveelement CWQ2, a second Wilkinson in-phase side inductive element LWI2, asecond Wilkinson quadrature-phase side inductive element LWQ2, a sixthDC blocking capacitive element CD6, a seventh DC blocking capacitiveelement CD7, and a eighth DC blocking capacitive element CD8.

The second in-phase phase-shift capacitive element CPI2 is coupledbetween the second in-phase input SII and a third internal node (notshown). The second in-phase phase-shift inductive element LPI2 iscoupled between the third internal node and the ground. The secondquadrature-phase phase-shift inductive element LPQ2 is coupled betweenthe second quadrature-phase input SQI and a fourth internal node (notshown). The second quadrature-phase phase-shift capacitive element CPQ2is coupled between the fourth internal node and the ground. The sixth DCblocking capacitive element CD6 and the second Wilkinson resistiveelement RW2 are coupled in series between the third internal node andthe fourth internal node. The second Wilkinson in-phase side capacitiveelement CWI2 is coupled between the third internal node and the ground.The second Wilkinson quadrature-phase side capacitive element CWQ2 iscoupled between the third internal node and the ground. The secondWilkinson in-phase side inductive element LWI2 is coupled in series withthe seventh DC blocking capacitive element CD7 between the thirdinternal node and the second quadrature combiner output SCO. The secondWilkinson quadrature-phase side inductive element LWQ2 is coupled inseries with the eighth DC blocking capacitive element CD8 between thefourth internal node and the second quadrature combiner output SCO. Thesecond Wilkinson capacitive element CW2 is coupled between the secondquadrature combiner output SCO and the ground.

FIG. 36 shows details of the first PA semiconductor die 210 illustratedin FIG. 30 according to one embodiment of the first PA semiconductor die210. The first PA semiconductor die 210 includes a first substrate andfunctional layers 234, multiple insulating layers 236, and multiplemetallization layers 238. Some of the insulating layers 236 may be usedto separate some of the metallization layers 238 from one another. Inone embodiment of the metallization layers 238, each of themetallization layers 238 is about parallel to at least another of themetallization layers 238. In this regard the metallization layers 238may be planar. In an alternate embodiment of the metallization layers238, the metallization layers 238 are formed over a non-planarstructure, such that spacing between pairs of the metallization layers238 is about constant. In one embodiment of the metallization layers238, each of the first pair 204 of tightly coupled inductors (FIG. 30)is constructed using at least one of the metallization layers 238.

Linear Mode and Non-Linear Mode Quadrature PA Circuitry

A summary of linear mode and non-linear mode quadrature PA circuitry ispresented, followed by a detailed description of the linear mode andnon-linear mode quadrature PA circuitry according to one embodiment ofthe present disclosure. Multi-mode multi-band RF PA circuitry includes amulti-mode multi-band quadrature RF PA coupled to multi-mode multi-bandswitching circuitry via a single output. The switching circuitryprovides at least one non-linear mode output and multiple linear modeoutputs. The non-linear mode output may be associated with at least onenon-linear mode RF communications band and each linear mode output maybe associated with a corresponding linear mode RF communications band.The outputs from the switching circuitry may be coupled to an antennaport via front-end aggregation circuitry. The quadrature nature of thequadrature PA path may provide tolerance for changes in antenna loadingconditions.

One embodiment of the RF PA circuitry includes a highband multi-modemulti-band quadrature RF PA coupled to highband multi-mode multi-bandswitching circuitry and a lowband multi-mode multi-band quadrature RF PAcoupled to lowband multi-mode multi-band switching circuitry. Thehighband switching circuitry may be associated with at least onehighband non-linear mode RF communications band and multiple highbandlinear mode RF communications bands. The lowband switching circuitry maybe associated with at least one lowband non-linear mode RFcommunications band and multiple lowband linear mode RF communicationsbands.

FIG. 37 shows details of the RF PA circuitry 30 illustrated in FIG. 5according to one embodiment of the RF PA circuitry 30. The RF PAcircuitry 30 illustrated in FIG. 37 is similar to the RF PA circuitry 30illustrated in FIG. 8, except in the RF PA circuitry 30 illustrated inFIG. 37, the first RF PA 50 is a first multi-mode multi-band quadratureRF PA; the second RF PA 54 is a second multi-mode multi-band quadratureRF PA; the alpha switching circuitry 52 is multi-mode multi-band RFswitching circuitry; the first RF PA 50 includes a single alpha PAoutput SAP; the second RF PA 54 includes a single beta PA output SBP;the alpha switching circuitry 52 further includes a first alphanon-linear mode output FANO, a first alpha linear mode output FALO, andup to and including an R^(TH) alpha linear mode output RALO; and thebeta switching circuitry 56 further includes a first beta non-linearmode output FBNO, a first beta linear mode output FBLO, and up to andincluding an S^(TH) beta linear mode output SBLO. In general, the alphaswitching circuitry 52 includes a group of alpha linear mode outputsFALO, RALO and the beta switching circuitry 56 includes a group of betalinear mode outputs FBLO, SBLO.

The first RF PA 50 is coupled to the alpha switching circuitry 52 viathe single alpha PA output SAP. The second RF PA 54 is coupled to thebeta switching circuitry 56 via the single beta PA output SBP. In oneembodiment of the first RF PA 50, the single alpha PA output SAP is asingle-ended output. In one embodiment of the second RF PA 54, thesingle beta PA output SBP is a single-ended output. In one embodiment ofthe alpha switching circuitry 52, the first alpha non-linear mode outputFANO is associated with a first non-linear mode RF communications bandand each of the group of alpha linear mode outputs FALO, RALO isassociated with a corresponding one of a first group of linear mode RFcommunications bands. In one embodiment of the beta switching circuitry56, the first beta non-linear mode output FBNO is associated with asecond non-linear mode RF communications band and each of the group ofbeta linear mode outputs FBLO, SBLO is associated with a correspondingone of a second group of linear mode RF communications bands.

In an alternate embodiment of the alpha switching circuitry 52, thefirst alpha non-linear mode output FANO is associated with a first groupof non-linear mode RF communications bands, which includes the firstnon-linear mode RF communications band. In an alternate embodiment ofthe beta switching circuitry 56, the first beta non-linear mode outputFBNO is associated with a second group of non-linear mode RFcommunications bands, which includes the second non-linear mode RFcommunications band.

In one embodiment of the RF communications system 26 (FIG. 5), the RFcommunications system 26 operates in one of a group of communicationsmodes. Control circuitry, which may include the control circuitry 42(FIG. 5), the PA control circuitry 94 (FIG. 13), or both, selects one ofthe group of communications modes. In one embodiment of the RFcommunications system 26, the group of communications modes includes afirst alpha non-linear mode and a group of alpha linear modes. In analternate embodiment of the RF communications system 26, the group ofcommunications modes includes the first alpha non-linear mode, the groupof alpha linear modes, a first beta non-linear mode, and a group of betanon-linear modes. In an additional embodiment of the RF communicationssystem 26, the group of communications modes includes a group of alphanon-linear modes, the group of alpha linear modes, a group of betanon-linear modes, and the group of beta non-linear modes. Otherembodiments of the RF communications system 26 may omit any or all ofthe communications modes. In one embodiment of the first alphanon-linear mode, the first alpha non-linear mode is a half-duplex mode.In one embodiment of the first beta non-linear mode, the beta alphanon-linear mode is a half-duplex mode. In one embodiment of the group ofalpha linear modes, each of the group of alpha linear modes is afull-duplex mode. In one embodiment of the group of beta linear modes,each of the group of beta linear modes is a full-duplex mode.

In one embodiment of the first RF PA 50, during the first alphanon-linear mode and during each of the group of alpha linear modes, thefirst RF PA 50 receives and amplifies the first RF input signal FRFI toprovide the first RF output signal FRFO via the single alpha PA outputSAP. Further, during the first beta non-linear mode and during each ofthe group of beta linear modes, the first RF PA 50 does not receive oramplify the first RF input signal FRFI to provide the first RF outputsignal FRFO.

In one embodiment of the second RF PA 54, during the first betanon-linear mode and during each of the group of beta linear modes, thesecond RF PA 54 receives and amplifies the second RF input signal SRFIto provide the second RF output signal SRFO via the single beta PAoutput SBP. Further, during the first alpha non-linear mode and duringeach of the group of alpha linear modes, the second RF PA 54 does notreceive or amplify the second RF input signal SRFI to provide the secondRF output signal SRFO.

In one embodiment of the alpha switching circuitry 52, during the firstalpha non-linear mode, the alpha switching circuitry 52 receives andforwards the first RF output signal FRFO to provide the first alpha RFtransmit signal FATX via the first alpha non-linear mode output FANO.During a first alpha linear mode, the alpha switching circuitry 52receives and forwards the first RF output signal FRFO to provide thesecond alpha RF transmit signal SATX via the first alpha linear modeoutput FALO. During an R^(TH) alpha linear mode, the alpha switchingcircuitry 52 receives and forwards the first RF output signal FRFO toprovide the P^(TH) alpha RF transmit signal PATX. In general, duringeach of the group of alpha linear modes, the alpha switching circuitry52 receives and forwards the first RF output signal FRFO to provide acorresponding one of a group of alpha RF transmit signals SATX, PATX viaa corresponding one of the group of alpha linear mode outputs FALO,RALO.

In one embodiment of the beta switching circuitry 56, during the firstbeta non-linear mode, the beta switching circuitry 56 receives andforwards the second RF output signal SRFO to provide the first beta RFtransmit signal FBTX via the first beta non-linear mode output FBNO.During a first beta linear mode, the beta switching circuitry 56receives and forwards the second RF output signal SRFO to provide thesecond beta RF transmit signal SBTX via the first beta linear modeoutput FBLO. During an S^(TH) beta linear mode, the beta switchingcircuitry 56 receives and forwards the second RF output signal SRFO toprovide the Q^(TH) beta RF transmit signal QBTX. In general, during eachof the group of beta linear modes, the beta switching circuitry 56receives and forwards the second RF output signal SRFO to provide acorresponding one of a group of beta RF transmit signals SBTX, QBTX viaa corresponding one of the group of beta linear mode outputs FBLO, SBLO.

FIG. 38 shows details of the RF PA circuitry 30 illustrated in FIG. 5according to an alternate embodiment of the RF PA circuitry 30. The RFPA circuitry 30 illustrated in FIG. 38 is similar to the RF PA circuitry30 illustrated in FIG. 9, except in the RF PA circuitry 30 illustratedin FIG. 38, the first RF PA 50 is the first multi-mode multi-bandquadrature RF PA; the second RF PA 54 is the second multi-modemulti-band quadrature RF PA; the alpha switching circuitry 52 ismulti-mode multi-band RF switching circuitry; the first RF PA 50includes the single alpha PA output SAP; the second RF PA 54 includesthe single beta PA output SBP; the alpha switching circuitry 52 furtherincludes the first alpha non-linear mode output FANO, a second alphanon-linear mode output SANO, the first alpha linear mode output FALO,and up to and including the R^(TH) alpha linear mode output RALO; andthe beta switching circuitry 56 further includes the first betanon-linear mode output FBNO, a second beta non-linear mode output SBNO,the first beta linear mode output FBLO, and up to and including theS^(TH) beta linear mode output SBLO. In general, the alpha switchingcircuitry 52 includes the group of alpha linear mode outputs FALO, RALOand the beta switching circuitry 56 includes the group of beta linearmode outputs FBLO, SBLO. Additionally, in general, the alpha switchingcircuitry 52 includes at least the first alpha harmonic filter 70 andthe beta switching circuitry 56 includes at least the first betaharmonic filter 74.

Dual-Path PA Circuitry with Harmonic Filters

A summary of dual-path PA circuitry with harmonic filters is presented,followed by a detailed description of the dual-path PA circuitry withharmonic filters according to one embodiment of the present disclosure.The dual-path PA circuitry includes a first transmit path and a secondtransmit path. Each transmit path has an RF PA and switching circuitryhaving at least one harmonic filter. Each RF PA may be coupled to itscorresponding switching circuitry via a single output. Each switchingcircuitry provides at least one output via a harmonic filter andmultiple outputs without harmonic filtering. The output via the harmonicfilter may be a non-linear mode output and the outputs without harmonicfiltering may be linear mode outputs. The non-linear mode output may beassociated with at least one non-linear mode RF communications band andthe linear mode outputs may be associated with multiple linear mode RFcommunications bands. As such, each RF PA may be a multi-mode multi-bandRF PA.

The outputs from the switching circuitry may be coupled to an antennaport via front-end aggregation circuitry. The quadrature nature of thequadrature PA path may provide tolerance for changes in antenna loadingconditions. One embodiment of the RF PA circuitry includes a highbandmulti-mode multi-band quadrature RF PA coupled to highband multi-modemulti-band switching circuitry and a lowband multi-mode multi-bandquadrature RF PA coupled to lowband multi-mode multi-band switchingcircuitry. The highband switching circuitry may be associated with atleast one highband non-linear mode RF communications band and multiplehighband linear mode RF communications bands. The lowband switchingcircuitry may be associated with at least one lowband non-linear mode RFcommunications band and multiple lowband linear mode RF communicationsbands.

In one embodiment of the RF PA circuitry 30, the first alpha non-linearmode output FANO is a first alpha output, the second alpha non-linearmode output SANO is a second alpha output, the first beta non-linearmode output FBNO is a first beta output, the second beta non-linear modeoutput SBNO is a second beta output, the group of alpha linear modeoutputs FALO, RALO is a group of alpha outputs, and the group of betalinear mode outputs FBLO, SBLO is a group of beta outputs. The alphaswitching circuitry 52 provides the first alpha output via the firstalpha harmonic filter 70. The alpha switching circuitry 52 provides thesecond alpha output via the second alpha harmonic filter 76. The alphaswitching circuitry 52 provides the group of alpha outputs withoutharmonic filtering. The beta switching circuitry 56 provides the firstbeta output via the first beta harmonic filter 74. The beta switchingcircuitry 56 provides the second beta output via the second betaharmonic filter 78. The beta switching circuitry 56 provides the groupof beta outputs without harmonic filtering.

In one embodiment of the RF communications system 26 (FIG. 5), the RFcommunications system 26 operates in one of a group of communicationsmodes. Control circuitry, which may include the control circuitry 42(FIG. 5), the PA control circuitry 94 (FIG. 13), or both, selects one ofthe group of communications modes. In one embodiment of the RFcommunications system 26, the group of communications modes includes thefirst alpha non-linear mode, the group of alpha linear modes, the firstbeta non-linear mode, and the group of beta non-linear modes. Otherembodiments of the RF communications system 26 may omit any or all ofthe communications modes. In one embodiment of the first alphanon-linear mode, the first alpha non-linear mode is a half-duplex mode.In one embodiment of the first beta non-linear mode, the beta alphanon-linear mode is a half-duplex mode. In one embodiment of the group ofalpha linear modes, each of the group of alpha linear modes is afull-duplex mode. In one embodiment of the group of beta linear modes,each of the group of beta linear modes is a full-duplex mode.

In one embodiment of the first RF PA 50, during the first alphanon-linear mode and during each of the group of alpha linear modes, thefirst RF PA 50 receives and amplifies the first RF input signal FRFI toprovide the first RF output signal FRFO via the single alpha PA outputSAP. Further, during the first beta non-linear mode and during each ofthe group of beta linear modes, the first RF PA 50 does not receive oramplify the first RF input signal FRFI to provide the first RF outputsignal FRFO.

In one embodiment of the second RF PA 54, during the first betanon-linear mode and during each of the group of beta linear modes, thesecond RF PA 54 receives and amplifies the second RF input signal SRFIto provide the second RF output signal SRFO via the single beta PAoutput SBP. Further, during the first alpha non-linear mode and duringeach of the group of alpha linear modes, the second RF PA 54 does notreceive or amplify the second RF input signal SRFI to provide the secondRF output signal SRFO.

In one embodiment of the alpha switching circuitry 52, during the firstalpha non-linear mode, the alpha switching circuitry 52 receives andforwards the first RF output signal FRFO to provide the first alpha RFtransmit signal FATX via the first alpha harmonic filter 70 and thefirst alpha output. During each of the group of alpha linear modes, thealpha switching circuitry 52 receives and forwards the first RF outputsignal FRFO to provide a corresponding one of a group of alpha RFtransmit signals TATX, PATX via a corresponding one of the group ofalpha outputs.

In one embodiment of the beta switching circuitry 56, during the firstbeta non-linear mode, the beta switching circuitry 56 receives andforwards the second RF output signal SRFO to provide the first beta RFtransmit signal FBTX via the first beta harmonic filter 74 and the firstbeta output. During each of the group of beta linear modes, the betaswitching circuitry 56 receives and forwards the second RF output signalSRFO to provide a corresponding one of a group of beta RF transmitsignals TBTX, QBTX via a corresponding one of the group of beta outputs.

FIG. 39 shows details of the RF PA circuitry 30 illustrated in FIG. 5according to an additional embodiment of the RF PA circuitry 30. The RFPA circuitry 30 illustrated in FIG. 39 is similar to the RF PA circuitry30 illustrated in FIG. 37, except the RF PA circuitry 30 illustrated inFIG. 39 further includes the switch driver circuitry 98 (FIG. 13) andshows details of the alpha RF switch 68 and the beta RF switch 72. Thealpha RF switch 68 includes a first alpha switching device 240, a secondalpha switching device 242, and a third alpha switching device 244. Thebeta RF switch 72 includes a first beta switching device 246, a secondbeta switching device 248, and a third beta switching device 250.Alternate embodiments of the alpha RF switch 68 may include any numberof alpha switching devices. Alternate embodiments of the beta RF switch72 may include any number of beta switching devices.

The first alpha switching device 240 is coupled between the single alphaPA output SAP and the first alpha harmonic filter 70. As such, the firstalpha switching device 240 is coupled between the single alpha PA outputSAP and the first alpha non-linear mode output FANO via the first alphaharmonic filter 70. The second alpha switching device 242 is coupledbetween the single alpha PA output SAP and the first alpha linear modeoutput FALO. The third alpha switching device 244 is coupled between thesingle alpha PA output SAP and the R^(TH) alpha linear mode output RALO.In general, the alpha RF switch 68 includes the first alpha switchingdevice 240 and a group of alpha switching devices, which includes thesecond alpha switching device 242 and the third alpha switching device244. As previously mentioned, the alpha switching circuitry 52 includesthe group of alpha linear mode outputs FALO, RALO. As such, each of thegroup of alpha switching devices 242, 244 is coupled between the singlealpha PA output SAP and a corresponding one of the group of alpha linearmode outputs FALO, RALO. Additionally, each of the alpha switchingdevices 240, 242, 244 has a corresponding control input, which iscoupled to the switch driver circuitry 98.

The first beta switching device 246 is coupled between the single betaPA output SBP and the first beta harmonic filter 74. As such, the firstbeta switching device 246 is coupled between the single beta PA outputSBP and the first beta non-linear mode output FBNO via the first betaharmonic filter 74. The second beta switching device 248 is coupledbetween the single beta PA output SBP and the first beta linear modeoutput FBLO. The third beta switching device 250 is coupled between thesingle beta PA output SBP and the S^(TH) beta linear mode output SBLO.In general, the beta RF switch 72 includes the first beta switchingdevice 246 and a group of beta switching devices, which includes thesecond beta switching device 248 and the third beta switching device250. As previously mentioned, the beta switching circuitry 56 includesthe group of beta linear mode outputs FBLO, SBLO. As such, each of thegroup of beta switching devices 248, 250 is coupled between the singlebeta PA output SBP and a corresponding one of the group of beta linearmode outputs FBLO, SBLO. Additionally, each of the beta switchingdevices 246, 248, 250 has a corresponding control input, which iscoupled to the switch driver circuitry 98.

In one embodiment of the alpha RF switch 68, the first alpha switchingdevice 240 includes multiple switching elements (not shown) coupled inseries. Each of the group of alpha switching devices 242, 244 includesmultiple switching elements (not shown) coupled in series. In oneembodiment of the beta RF switch 72, the first beta switching device 246includes multiple switching elements (not shown) coupled in series. Eachof the group of beta switching devices 248, 250 includes multipleswitching elements (not shown) coupled in series.

PA Bias Supply Using Boosted Voltage

A summary of a PA bias supply using boosted voltage is presented,followed by a detailed description of the PA bias supply using boostedvoltage according to one embodiment of the present disclosure. An RF PAbias power supply signal is provided to RF PA circuitry by boosting avoltage from a DC power supply, such as a battery. In this regard, aDC-DC converter receives a DC power supply signal from the DC powersupply. The DC-DC converter provides the bias power supply signal basedon the DC power supply signal, such that a voltage of the bias powersupply signal is greater than a voltage of the DC power supply signal.The RF PA circuitry has an RF PA, which has a final stage that receivesa final bias signal to bias the final stage, such that the final biassignal is based on the bias power supply signal. Boosting the voltagefrom the DC power supply may provide greater flexibility in biasing theRF PA.

In one embodiment of the DC-DC converter, the DC-DC converter includes acharge pump, which may receive and pump-up the DC power supply signal toprovide the bias power supply signal. Further, the DC-DC converter mayoperate in one of a bias supply pump-up operating mode and at least oneother operating mode, which may include any or all of a bias supplypump-even operating mode, a bias supply pump-down operating mode, and abias supply bypass operating mode. Additionally, the DC-DC converterprovides an envelope power supply signal to the RF PA, which uses theenvelope power supply signal to provide power for amplification. In oneembodiment of the RF PA circuitry, the RF PA circuitry includes PA biascircuitry, which receives the bias power supply signal to provide thefinal bias signal. The PA bias circuitry may include a final stagecurrent analog-to-digital converter (IDAC) to receive and use the biaspower supply signal in a digital-to-analog conversion to provide thefinal bias signal.

In an alternate embodiment of the RF PA circuitry, the RF PA circuitryincludes a first RF PA and a second RF PA, which include a first finalstage and a second final stage, respectively. The first RF PA may beused to receive and amplify a highband RF input signal and the second RFPA may be used to receive and amplify a lowband RF input signal. The RFPA circuitry operates in one of a first PA operating mode and a secondPA operating mode, such that during the first PA operating mode, thefirst RF PA is active and the second RF PA is disabled. Conversely,during the second PA operating mode, the first RF PA is disabled and thesecond RF PA is active. The PA bias circuitry may include the finalstage IDAC and a final stage multiplexer. The final stage IDAC receivesand uses the bias power supply signal in a digital-to-analog conversionto provide a final stage bias signal to the final stage multiplexer.During the first PA operating mode, the final stage multiplexer receivesand forwards the final stage bias signal to provide a first final biassignal to the first RF PA to bias the first final stage. During thesecond PA operating mode, the final stage multiplexer receives andforwards the final stage bias signal to provide a second final biassignal to the second RF PA to bias the second final stage.

FIG. 40 shows details of the first RF PA 50, the second RF PA 54, andthe PA bias circuitry 96 illustrated in FIG. 13 according to oneembodiment of the first RF PA 50, the second RF PA 54, and the PA biascircuitry 96. The first RF PA 50 includes a first driver stage 252 and afirst final stage 254. The second RF PA 54 includes a second driverstage 256 and a second final stage 258. The PA bias circuitry 96includes driver stage IDAC circuitry 260 and final stage IDAC circuitry262. In general, the first RF PA 50 receives and amplifies the first RFinput signal FRFI to provide the first RF output signal FRFO. Similarly,the second RF PA 54 receives and amplifies the second RF input signalSRFI to provide the second RF output signal SRFO. Specifically, thefirst driver stage 252 receives and amplifies the first RF input signalFRFI to provide a first final stage input signal FFSI, and the firstfinal stage 254 receives and amplifies the first final stage inputsignal FFSI to provide the first RF output signal FRFO. Similarly, thesecond driver stage 256 receives and amplifies the second RF inputsignal SRFI to provide a second final stage input signal SFSI, and thesecond final stage 258 receives and amplifies the second final stageinput signal SFSI to provide the second RF output signal SRFO.

The first driver stage 252 receives the envelope power supply signalEPS, which provides power for amplification; the first final stage 254receives the envelope power supply signal EPS, which provides power foramplification; the second driver stage 256 receives the envelope powersupply signal EPS, which provides power for amplification; and thesecond final stage 258 receives the envelope power supply signal EPS,which provides power for amplification. In general, the first RF PA 50receives the first driver bias signal FDB to bias first driver stage 252and receives the first final bias signal FFB to bias the first finalstage 254. Specifically, the first driver stage 252 receives the firstdriver bias signal FDB to bias the first driver stage 252 and the firstfinal stage 254 receives the first final bias signal FFB to bias thefirst final stage 254. Similarly, the second RF PA 54 receives thesecond driver bias signal SDB to bias the second driver stage 256 andreceives the second final bias signal SFB to bias the second final stage258. Specifically, the second driver stage 256 receives the seconddriver bias signal SDB to bias the second driver stage 256 and thesecond final stage 258 receives the second final bias signal SFB to biasthe second final stage 258.

In general, the PA bias circuitry 96 provides the first driver biassignal FDB based on the bias power supply signal BPS, the first finalbias signal FFB based on the bias power supply signal BPS, the seconddriver bias signal SDB based on the bias power supply signal BPS, andthe second final bias signal SFB based on the bias power supply signalBPS. Specifically, the driver stage IDAC circuitry 260 provides thefirst driver bias signal FDB based on the bias power supply signal BPSand provides the second driver bias signal SDB based on the bias powersupply signal BPS. Similarly, the final stage IDAC circuitry 262provides the first final bias signal FFB based on the bias power supplysignal BPS and provides the second final bias signal SFB based on thebias power supply signal BPS.

In one embodiment of the driver stage IDAC circuitry 260 and the finalstage IDAC circuitry 262, the driver stage IDAC circuitry 260 and thefinal stage IDAC circuitry 262 receive the bias power supply signal BPSand the bias configuration control signal BCC. The driver stage IDACcircuitry 260 provides the first driver bias signal FDB and the seconddriver bias signal SDB based on the bias power supply signal BPS and thebias configuration control signal BCC. The final stage IDAC circuitry262 provides the first final bias signal FFB and the second final biassignal SFB based on the bias power supply signal BPS and the biasconfiguration control signal BCC. The bias power supply signal BPSprovides the power necessary to generate the bias signals FDB, FFB, SDB,SFB. A selected magnitude of each of the bias signals FDB, FFB, SDB, SFBis provided by the driver stage IDAC circuitry 260 and the final stageIDAC circuitry 262. In one embodiment of the RF PA circuitry 30, the PAcontrol circuitry 94 selects the magnitude of any or all of the biassignals FDB, FFB, SDB, SFB and communicates the magnitude selections tothe driver stage IDAC circuitry 260 and the final stage IDAC circuitry262 via the bias configuration control signal BCC. The magnitudeselections by the PA control circuitry 94 may be based on the PAconfiguration control signal PCC. In an alternate embodiment of the RFPA circuitry 30, the control circuitry 42 (FIG. 5) selects the magnitudeof any or all of the bias signals FDB, FFB, SDB, SFB and communicatesthe magnitude selections to the driver stage IDAC circuitry 260 and thefinal stage IDAC circuitry 262 via the PA control circuitry 94.

As previously discussed, in one embodiment of the RF PA circuitry 30,the RF PA circuitry 30 operates in one of the first PA operating modeand the second PA operating mode. During the first PA operating mode,the first RF PA 50 receives and amplifies the first RF input signal FRFIto provide the first RF output signal FRFO, and the second RF PA 54 isdisabled. During the second PA operating mode, the second RF PA 54receives and amplifies the second RF input signal SRFI to provide thesecond RF output signal SRFO, and the first RF PA 50 is disabled.

In one embodiment of the first RF PA 50, during the second PA operatingmode, the first RF PA 50 is disabled via the first driver bias signalFDB. As such, the first driver stage 252 is disabled. In an alternateembodiment of the first RF PA 50, during the second PA operating mode,the first RF PA 50 is disabled via the first final bias signal FFB. Assuch, the first final stage 254 is disabled. In an additional embodimentof the first RF PA 50, during the second PA operating mode, the first RFPA 50 is disabled via both the first driver bias signal FDB and thefirst final bias signal FFB. As such, both the first driver stage 252and the first final stage 254 are disabled.

In one embodiment of the second RF PA 54, during the first PA operatingmode, the second RF PA 54 is disabled via the second driver bias signalSDB. As such, the second driver stage 256 is disabled. In an alternateembodiment of the second RF PA 54, during the first PA operating mode,the second RF PA 54 is disabled via the second final bias signal SFB. Assuch, the second final stage 258 is disabled. In an additionalembodiment of the second RF PA 54, during the first PA operating mode,the second RF PA 54 is disabled via both the second driver bias signalSDB and the second final bias signal SFB. As such, both the seconddriver stage 256 and the second final stage 258 are disabled.

In one embodiment of the RF PA circuitry 30, the PA control circuitry 94selects the one of the first PA operating mode and the second PAoperating mode. As such, the PA control circuitry 94 may control any orall of the bias signals FDB, FFB, SDB, SFB via the bias configurationcontrol signal BCC based on the PA operating mode selection. The PAoperating mode selection may be based on the PA configuration controlsignal PCC. In an alternate embodiment of the RF PA circuitry 30, thecontrol circuitry 42 (FIG. 5) selects the one of the first PA operatingmode and the second PA operating mode. As such, the control circuitry 42(FIG. 5) may indicate the operating mode selection to the PA controlcircuitry 94 via the PA configuration control signal PCC. In anadditional embodiment of the RF PA circuitry 30, the RF modulation andcontrol circuitry 28 (FIG. 5) selects the one of the first PA operatingmode and the second PA operating mode. As such, the RF modulation andcontrol circuitry 28 (FIG. 5) may indicate the operating mode selectionto the PA control circuitry 94 via the PA configuration control signalPCC. In general, selection of the PA operating mode is made by controlcircuitry, which may be any of the PA control circuitry 94, the RFmodulation and control circuitry 28 (FIG. 5), and the control circuitry42 (FIG. 5).

Further, during the first PA operating mode, the control circuitryselects a desired magnitude of the first driver bias signal FDB, adesired magnitude of the first final bias signal FFB, or both. Duringthe second PA operating mode, the control circuitry selects a desiredmagnitude of the second driver bias signal SDB, a desired magnitude ofthe second final bias signal SFB, or both As such, during the first PAoperating mode, the PA control circuitry 94 provides the biasconfiguration control signal BCC to the PA bias circuitry 96 in generaland to the driver stage IDAC circuitry 260 in particular based on thedesired magnitude of the first driver bias signal FDB, and the PAcontrol circuitry 94 provides the bias configuration control signal BCCto the PA bias circuitry 96 in general and to the final stage IDACcircuitry 262 in particular based on the desired magnitude of the firstfinal bias signal FFB. During the second PA operating mode, the PAcontrol circuitry 94 provides the bias configuration control signal BCCto the PA bias circuitry 96 in general and to the driver stage IDACcircuitry 260 in particular based on the desired magnitude of the seconddriver bias signal SDB, and the PA control circuitry 94 provides thebias configuration control signal BCC to the PA bias circuitry 96 ingeneral and to the final stage IDAC circuitry 262 in particular based onthe desired magnitude of the second final bias signal SFB. In oneembodiment of the PA control circuitry 94, the bias configurationcontrol signal BCC is a digital signal.

FIG. 41 shows details of the driver stage IDAC circuitry 260 and thefinal stage IDAC circuitry 262 illustrated in FIG. 40 according to oneembodiment of the driver stage IDAC circuitry 260 and the final stageIDAC circuitry 262. The driver stage IDAC circuitry 260 includes adriver stage IDAC 264, a driver stage multiplexer 266, and driver stagecurrent reference circuitry 268. The final stage IDAC circuitry 262includes a final stage IDAC 270, a final stage multiplexer 272, andfinal stage current reference circuitry 274.

The driver stage IDAC 264 receives the bias power supply signal BPS, thebias configuration control signal BCC, and a driver stage referencecurrent IDSR. As such, the driver stage IDAC 264 uses the bias powersupply signal BPS and the driver stage reference current IDSR in adigital-to-analog conversion to provide a driver stage bias signal DSBS.A magnitude of the digital-to-analog conversion is based on the biasconfiguration control signal BCC. The driver stage current referencecircuitry 268 is coupled to the driver stage IDAC 264 and provides thedriver stage reference current IDSR to the driver stage IDAC 264, suchthat during the first PA operating mode, the first driver bias signalFDB is based on the driver stage reference current IDSR, and during thesecond PA operating mode, the second driver bias signal SDB is based onthe driver stage reference current IDSR. The driver stage currentreference circuitry 268 may be disabled based on the bias configurationcontrol signal BCC. The driver stage current reference circuitry 268 andthe driver stage multiplexer 266 receive the bias configuration controlsignal BCC. The driver stage multiplexer 266 receives and forwards thedriver stage bias signal DSBS, which is a current signal, to provideeither the second driver bias signal SDB or the first driver bias signalFDB based on the bias configuration control signal BCC. During the firstPA operating mode, the driver stage multiplexer 266 receives andforwards the driver stage bias signal DSBS to provide the first driverbias signal FDB based on the bias configuration control signal BCC.During the second PA operating mode, the driver stage multiplexer 266receives and forwards the driver stage bias signal DSBS to provide thesecond driver bias signal SDB based on the bias configuration controlsignal BCC.

In this regard, during the first PA operating mode, the driver stageIDAC 264 provides the first driver bias signal FDB via the driver stagemultiplexer 266, such that a magnitude of the first driver bias signalFDB is about equal to the desired magnitude of the first driver biassignal FDB. During the second PA operating mode, the driver stage IDAC264 provides the second driver bias signal SDB via the driver stagemultiplexer 266, such that a magnitude of the second driver bias signalSDB is about equal to the desired magnitude of the second driver biassignal SDB.

In one embodiment of the driver stage multiplexer 266, during the firstPA operating mode, the driver stage multiplexer 266 disables the secondRF PA 54 via the second driver bias signal SDB. In one embodiment of thesecond RF PA 54, the second RF PA 54 is disabled when the second driverbias signal SDB is about zero volts. In one embodiment of the driverstage multiplexer 266, during the second PA operating mode, the driverstage multiplexer 266 disables the first RF PA 50 via the first driverbias signal FDB. In one embodiment of the first RF PA 50, the first RFPA 50 is disabled when the first driver bias signal FDB is about zerovolts. As such, in one embodiment of the driver stage multiplexer 266,during the first PA operating mode, the driver stage multiplexer 266provides the second driver bias signal SDB, which is about zero volts,such that the second RF PA 54 is disabled, and during the second PAoperating mode, the driver stage multiplexer 266 provides the firstdriver bias signal FDB, which is about zero volts, such that the firstRF PA 50 is disabled.

The final stage IDAC 270 receives the bias power supply signal BPS, thebias configuration control signal BCC, and a final stage referencecurrent IFSR. As such, the final stage IDAC 270 uses the bias powersupply signal BPS and the final stage reference current IFSR in adigital-to-analog conversion to provide a final stage bias signal FSBS.A magnitude of the digital-to-analog conversion is based on the biasconfiguration control signal BCC. The final stage current referencecircuitry 274 is coupled to the final stage IDAC 270 and provides thefinal stage reference current IFSR to the final stage IDAC 270, suchthat during the first PA operating mode, the first final bias signal FFBis based on the final stage reference current IFSR, and during thesecond PA operating mode, the second final bias signal SFB is based onthe final stage reference current IFSR. The final stage currentreference circuitry 274 and the final stage IDAC 270 receive the biasconfiguration control signal BCC. The final stage current referencecircuitry 274 may be disabled based on the bias configuration controlsignal BCC. The final stage multiplexer 272 receives and forwards thefinal stage bias signal FSBS, which is a current signal, to provideeither the second final bias signal SFB or the first final bias signalFFB based on the bias configuration control signal BCC. During the firstPA operating mode, the final stage multiplexer 272 receives and forwardsthe final stage bias signal FSBS to provide the first final bias signalFFB based on the bias configuration control signal BCC. During thesecond PA operating mode, the final stage multiplexer 272 receives andforwards the final stage bias signal FSBS to provide the second finalbias signal SFB based on the bias configuration control signal BCC.

In this regard, during the first PA operating mode, the final stage IDAC270 provides the first final bias signal FFB via the final stagemultiplexer 272, such that a magnitude of the first final bias signalFFB is about equal to the desired magnitude of the first final biassignal FFB. Specifically, the final stage IDAC 270 receives and uses thebias power supply signal BPS and the bias configuration control signalBCC in a digital-to-analog conversion to provide the first final biassignal FFB. During the second PA operating mode, the final stage IDAC270 provides the second final bias signal SFB via the final stagemultiplexer 272, such that a magnitude of the second final bias signalSFB is about equal to the desired magnitude of the second final biassignal SFB. Specifically, the final stage IDAC 270 receives and uses thebias power supply signal BPS and the bias configuration control signalBCC in a digital-to-analog conversion to provide the second final biassignal SFB.

In one embodiment of the final stage multiplexer 272, during the firstPA operating mode, the final stage multiplexer 272 disables the secondRF PA 54 via the second final bias signal SFB. In one embodiment of thesecond RF PA 54, the second RF PA 54 is disabled when the second finalbias signal SFB is about zero volts. In one embodiment of the finalstage multiplexer 272, during the second PA operating mode, the finalstage multiplexer 272 disables the first RF PA 50 via the first finalbias signal FFB. In one embodiment of the first RF PA 50, the first RFPA 50 is disabled when the first final bias signal FFB is about zerovolts. As such, in one embodiment of the final stage multiplexer 272,during the first PA operating mode, the final stage multiplexer 272provides the second final bias signal SFB, which is about zero volts,such that the second RF PA 54 is disabled, and during the second PAoperating mode, the final stage multiplexer 272 provides the first finalbias signal FFB, which is about zero volts, such that the first RF PA 50is disabled.

FIG. 42 shows details of the driver stage current reference circuitry268 and the final stage current reference circuitry 274 illustrated inFIG. 41 according to one embodiment of the driver stage currentreference circuitry 268 and the final stage current reference circuitry274. The driver stage current reference circuitry 268 includes a driverstage temperature compensation circuit 276 to temperature compensate thedriver stage reference current IDSR. The final stage current referencecircuitry 274 includes a final stage temperature compensation circuit278 to temperature compensate the final stage reference current IFSR.

Charge Pump Based PA Envelope Power Supply and Bias Power Supply

A summary of a charge pump based PA envelope power supply and bias powersupply is presented, followed by a detailed description of the chargepump based PA envelope power supply according to one embodiment of thepresent disclosure. The present disclosure relates to a DC-DC converter,which includes a charge pump based RF PA envelope power supply and acharge pump based PA bias power supply. The DC-DC converter is coupledbetween RF PA circuitry and a DC power supply, such as a battery. Assuch, the PA envelope power supply provides an envelope power supplysignal to the RF PA circuitry and the PA bias power supply provides abias power supply signal to the RF PA circuitry. Both the PA envelopepower supply and the PA bias power supply receive power via a DC powersupply signal from the DC power supply. The PA envelope power supplyincludes a charge pump buck converter and the PA bias power supplyincludes a charge pump.

By using charge pumps, a voltage of the envelope power supply signal maybe greater than a voltage of the DC power supply signal, a voltage ofthe bias power supply signal may be greater than the voltage of the DCpower supply signal, or both. Providing boosted voltages may providegreater flexibility in providing envelope power for amplification and inbiasing the RF PA circuitry. The charge pump buck converter provides thefunctionality of a charge pump feeding a buck converter. However, thecharge pump buck converter requires fewer switching elements than acharge pump feeding a buck converter by sharing certain switchingelements.

The charge pump buck converter is coupled between the DC power supplyand the RF PA circuitry. The charge pump is coupled between the DC powersupply and the RF PA circuitry. In one embodiment of the PA envelopepower supply, the PA envelope power supply further includes a buckconverter coupled between the DC power supply and the RF PA circuitry.The PA envelope power supply may operate in one of a first envelopeoperating mode and a second envelope operating mode. During the firstenvelope operating mode, the charge pump buck converter is active, andthe buck converter is inactive. Conversely, during the second envelopeoperating mode, the charge pump buck converter is inactive, and the buckconverter is active. As such, the PA envelope power supply may operatein the first envelope operating mode when a voltage above the voltage ofthe DC power supply signal may be needed. Conversely, the PA envelopepower supply may operate in the second envelope operating mode when avoltage above the voltage of the DC power supply signal is not needed.

In one embodiment of the charge pump buck converter, the charge pumpbuck converter operates in one of a pump buck pump-up operating mode andat least one other pump buck operating mode, which may include any orall of a pump buck pump-down operating mode, a pump buck pump-evenoperating mode, and a pump buck bypass operating mode. In one embodimentof the charge pump, the charge pump operates in one of a bias supplypump-up operating mode and at least one other bias supply operatingmode, which may include any or all of a bias supply pump-down operatingmode, a bias supply pump-even operating mode, and a bias supply bypassoperating mode.

In one embodiment of the RF PA circuitry, the RF PA circuitry has an RFPA, which is biased based on the bias power supply signal and receivesthe envelope power supply signal to provide power for amplification.

In one embodiment of the RF PA circuitry, the RF PA has a final stagethat receives a final bias signal to bias the final stage, such that thefinal bias signal is based on the bias power supply signal.Additionally, the DC-DC converter provides the envelope power supplysignal to the RF PA, which uses the envelope power supply signal toprovide power for amplification. In one embodiment of the RF PAcircuitry, the RF PA circuitry includes PA bias circuitry, whichreceives the bias power supply signal to provide the final bias signal.In one embodiment of the PA bias circuitry, the PA bias circuitryincludes a final stage IDAC to receive and use the bias power supplysignal in a digital-to-analog conversion to provide the final biassignal.

In one embodiment of the RF PA circuitry, the RF PA circuitry includes afirst RF PA and a second RF PA, which may include a first final stageand a second final stage, respectively. The first RF PA is used toreceive and amplify a highband RF input signal and the second RF PA isused to receive and amplify a lowband RF input signal. The RF PAcircuitry may operate in one of a first PA operating mode and a secondPA operating mode, such that during the first PA operating mode, thefirst RF PA is active and the second RF PA is disabled. Conversely,during the second PA operating mode, the first RF PA is disabled and thesecond RF PA is active. The PA bias circuitry includes the final stageIDAC and a final stage multiplexer. The final stage IDAC receives anduses the bias power supply signal in a digital-to-analog conversion toprovide a final stage bias signal to the final stage multiplexer. Duringthe first PA operating mode, the final stage multiplexer receives andforwards the final stage bias signal to provide a first final biassignal to the first RF PA to bias the first final stage. During thesecond PA operating mode, the final stage multiplexer receives andforwards the final stage bias signal to provide a second final biassignal to the second RF PA to bias the second final stage.

Interference Reduction Between RF Communications Bands

Embodiments of the present disclosure relate to RF PA circuitry and a PAenvelope power supply. The RF PA circuitry receives and amplifies an RFinput signal to provide an RF output signal using an envelope powersupply signal, which is provided by the PA envelope power supply. The RFPA circuitry operates in either a normal RF spectral emissions mode or areduced RF spectral emissions mode. When reduced RF spectral emissionsare required, the RF PA circuitry operates in the reduced RF spectralemissions mode. As such, at a given RF output power, during the reducedRF spectral emissions mode, RF spectral emissions of the RF outputsignal are less than during the normal RF spectral emissions mode. As aresult, the reduced RF spectral emissions mode may be used to reduceinterference between RF communications bands.

Cellular communications bands are often adjacent to non-cellularcommunications bands. As such, interference between the cellularcommunications bands and the non-cellular communications bands needs tobe minimized for the corresponding cellular and the non-cellular systemsto operate properly and efficiently. For example, RF emissions fromcellular communications signals that bleed into a non-cellularcommunications band must be low enough to prevent problems in thecorresponding non-cellular communications system. Such RF emissions maybe called RF spectral emissions since these emissions fall outside of adesired RF spectrum associated with a corresponding cellularcommunications signal.

The RF spectral emissions from a cellular communications signal mayadversely impact the non-cellular communications system. However, whenthe cellular communications band is adequately separated from thenon-cellular communications band, when a magnitude of the cellularcommunications signal having RF spectral emissions is sufficientlysmall, when a sensitivity of the corresponding non-cellularcommunications system to the RF spectral emissions is sufficientlysmall, or any combination thereof, the cellular communications signaldoes not adversely impact the non-cellular communications system.

In this regard, when the cellular communications band is about adjacentto the non-cellular communications band and the non-cellularcommunications system is sensitive to the RF spectral emissions, the RFspectral emissions must be limited to allow the non-cellularcommunications system to function properly. As such, the RF spectralemissions may be limited by limiting the magnitude of the cellularcommunications signal, by reducing characteristic RF spectral emissionsof the cellular communications signal, or both. The characteristic RFspectral emissions may be reduced by increasing linearity in an RF PA,by improving a quadrature balance of a quadrature RF PA, or both.

As previously mentioned, the DC-DC converter 32 (FIG. 2) provides theenvelope power supply signal EPS to the RF PA circuitry 30 (FIG. 2). TheRF PA circuitry 30 (FIG. 14) includes the PA-DCI 60 (FIG. 14), the PAcontrol circuitry 94 (FIG. 14), the first RF PA 50 (FIG. 14), and thesecond RF PA 54 (FIG. 14). The PA-DCI 60 (FIG. 14) is coupled betweenthe PA control circuitry 94 (FIG. 14) and the digital communications bus66 (FIG. 14). The DC-DC converter 32 (FIG. 2) provides the envelopepower supply signal EPS to the first RF PA 50 (FIG. 14) and to thesecond RF PA 54 (FIG. 14). The PA bias circuitry 96 (FIG. 14) providesthe first driver bias signal FDB and the first final bias signal FFB tothe first RF PA 50 (FIG. 14) based on the bias power supply signal BPSand the bias configuration control signal BCC. The PA bias circuitry 96(FIG. 14) provides the second driver bias signal SDB and the secondfinal bias signal SFB to the second RF PA 54 (FIG. 14) based on the biaspower supply signal BPS and the bias configuration control signal BCC.As such, the PA bias circuitry 96 (FIG. 14) is coupled between the PAcontrol circuitry 94 (FIG. 14) and the RF PAs 50, 54 (FIG. 14).

The first RF PA 50 (FIG. 14) receives and amplifies the first RF inputsignal FRFI to provide the first RF output signal FRFO using theenvelope power supply signal EPS. The second RF PA 54 (FIG. 14) receivesand amplifies the second RF input signal SRFI to provide the second RFoutput signal SRFO using the envelope power supply signal EPS. Ingeneral, the RF PA circuitry 30 (FIG. 14) receives and amplifies an RFinput signal to provide an RF output signal using the envelope powersupply signal EPS (FIG. 14). Further, in general, the RF PA circuitry 30(FIG. 14) includes an RF PA, which receives and amplifies the RF inputsignal to provide the RF output signal using the envelope power supplysignal EPS. In one embodiment of the RF PA, the RF PA is a quadrature RFPA, which receives and amplifies the RF input signal to provide the RFoutput signal using the envelope power supply signal EPS. In thisregard, the PA bias circuitry 96 (FIG. 14) is coupled between the PAcontrol circuitry 94 (FIG. 14) and the RF PAs.

In a first embodiment of the RF PA circuitry 30 (FIG. 14), the RF PA isthe first RF PA 50 (FIG. 14), the RF input signal is the first RF inputsignal FRFI and the RF output signal is the first RF output signal FRFO.In a second embodiment of the RF PA circuitry 30 (FIG. 14), the RF PA isthe second RF PA 54 (FIG. 14), the RF input signal is the second RFinput signal SRFI and the RF output signal is the second RF outputsignal SRFO.

In one embodiment of the RF PA circuitry 30 (FIG. 40), the first RF PA50 (FIG. 40) includes the first driver stage 252 (FIG. 40) and the firstfinal stage 254 (FIG. 40). The second RF PA 54 (FIG. 40) includes thesecond driver stage 256 (FIG. 40) and the second final stage 258 (FIG.40). In one embodiment of the RF PA, the RF PA includes a driver stageand a final stage. In an exemplary embodiment of the RF PA, the driverstage is the first driver stage 252 (FIG. 40) and the final stage is thefirst final stage 254 (FIG. 40). In an alternate exemplary embodiment ofthe RF PA, the driver stage is the second driver stage 256 (FIG. 40) andthe final stage is the second final stage 258 (FIG. 40). In oneembodiment of the quadrature RF PA, the RF PA includes a quadraturedriver stage and a quadrature final stage. In an exemplary embodiment ofthe quadrature RF PA, the quadrature driver stage is the first driverstage 252 (FIG. 40) and the quadrature final stage is the first finalstage 254 (FIG. 40). In an alternate exemplary embodiment of thequadrature RF PA, the quadrature driver stage is the second driver stage256 (FIG. 40) and the quadrature final stage is the second final stage258 (FIG. 40).

In one embodiment of the RF PA circuitry 30 (FIG. 14), the RF PAcircuitry 30 (FIG. 14) operates in one of a normal RF spectral emissionsmode and a reduced RF spectral emissions mode. When reduced RF spectralemissions are required, the RF PA circuitry 30 (FIG. 14) operates in thereduced RF spectral emissions mode. At a given RF output power, duringthe reduced RF spectral emissions mode, RF spectral emissions of the RFoutput signal are less than during the normal RF spectral emissionsmode.

In one embodiment of the RF PA circuitry 30 (FIG. 14), when reduced RFspectral emissions are not required, the RF PA circuitry 30 (FIG. 14)operates in the normal RF spectral emissions mode. In an alternateembodiment of the RF PA circuitry 30 (FIG. 14), the RF PA circuitry 30(FIG. 14) is hardwired to select the reduced RF spectral emissions mode,such that the reduced RF spectral emissions mode is continuouslyselected. In an additional embodiment of the RF PA circuitry 30 (FIG.14), the PA control circuitry 94 (FIG. 14) selects the one of the normalRF spectral emissions mode and the reduced RF spectral emissions mode.

In one embodiment of the RF PA circuitry 30 (FIG. 14), the RF outputsignal falls within one of a group of RF communications bands, such thatthe group of RF communications bands includes a first RF communicationsband, which is about adjacent to a second RF communications band. In oneembodiment of the RF PA circuitry 30 (FIG. 14), when the one of thegroup of RF communications bands is the first RF communications band,reduced RF spectral emissions are required. In an alternate embodimentof the RF PA circuitry 30 (FIG. 14), when the one of the group of RFcommunications bands is the first RF communications band and an RFoutput power from the RF PA is higher than an RF output power threshold,reduced RF spectral emissions are required.

In one embodiment of the RF PA circuitry 30 (FIG. 14), the first RFcommunications band is a cellular communications band and the second RFcommunications band is a non-cellular communications band. In oneembodiment of the first RF communications band, the first RFcommunications band is a 3^(rd) Generation Partnership Project (3GPP)cellular communications band. In one embodiment of the 3GPP cellularcommunications band, the 3GPP cellular communications band is a 3GPPlong term evolution (3GPP-LTE) cellular communications band. In oneembodiment of the first RF communications band, a frequency range of thefirst RF communications band is between about 777 megahertz and about787 megahertz. In one embodiment of the second RF communications band,the second RF communications band is a Public Safety Band, which is anon-cellular communications band. In one embodiment of the second RFcommunications band, a frequency range of the second RF communicationsband is between about 788 megahertz and about 798 megahertz.

In one embodiment of the RF PA circuitry 30 (FIG. 14), during thereduced RF spectral emissions mode, the RF PA has higher PA linearitythan during the normal RF spectral emissions mode. As such, to providehigher linearity, in one embodiment of the RF PA circuitry 30 (FIG. 14),during the reduced RF spectral emissions mode, the RF PA has a higher PAbias level than during the normal RF spectral emissions mode. Further,to provide higher linearity, in one embodiment of the RF PA circuitry 30(FIG. 14), at a given RF output power, during the reduced RF spectralemissions mode, a magnitude of the envelope power supply signal EPS(FIG. 14) is higher than during the normal RF spectral emissions mode.

In one embodiment of the RF PA circuitry 30 (FIG. 14), during thereduced RF spectral emissions mode, a quadrature balance of thequadrature RF PA is better than during the normal RF spectral emissionsmode. The quadrature balance is better when a signal level in anin-phase path of the quadrature RF PA is closer to matching a signallevel in a quadrature-phase path of the quadrature RF PA. In analternate embodiment of the RF PA circuitry 30 (FIG. 14), during thereduced RF spectral emissions mode, a quadrature balance of thequadrature RF PA is better and the quadrature RF PA has higher PAlinearity than during the normal RF spectral emissions mode.

In one embodiment of the RF PA circuitry 30 (FIG. 14), during thereduced RF spectral emissions mode, a quadrature balance of thequadrature final stage is better than during the normal RF spectralemissions mode. In one embodiment of the quadrature final stage, duringthe reduced RF spectral emissions mode, a bias level of the quadraturefinal stage is different than during the normal RF spectral emissionsmode to improve quadrature balance of the quadrature final stage.

In one embodiment of the RF PA circuitry 30 (FIG. 14), during thereduced RF spectral emissions mode, a quadrature balance of thequadrature driver stage is better than during the normal RF spectralemissions mode. In one embodiment of the quadrature driver stage, duringthe reduced RF spectral emissions mode, a bias level of the quadraturedriver stage is different than during the normal RF spectral emissionsmode to improve quadrature balance of the quadrature driver stage.

In an alternate embodiment of the RF PA circuitry 30 (FIG. 14), duringthe reduced RF spectral emissions mode, a quadrature balance of thequadrature final stage is better and a quadrature balance of thequadrature driver stage is better than during the normal RF spectralemissions mode. In one embodiment of the quadrature final stage and thequadrature driver stage, during the reduced RF spectral emissions mode,a bias level of the quadrature final stage is different and a bias levelof the quadrature driver stage is different than during the normal RFspectral emissions mode to improve quadrature balance of the quadraturefinal stage and the quadrature driver stage.

In one embodiment of the RF PA circuitry 30 (FIG. 14), the PA controlcircuitry 94 (FIG. 14) receives information via the digitalcommunications bus 66 (FIG. 14) and selects the one of the normal RFspectral emissions mode and the reduced RF spectral emissions mode basedon the information. In one embodiment of the RF PA circuitry 30 (FIG.14), the RF output signal falls within one of the group of RFcommunications bands and the information identifies the one of the groupof RF communications bands. In one embodiment of the RF PA circuitry 30(FIG. 14), the information is indicative of the RF output power from theRF PAs. In one embodiment of the RF PA circuitry 30 (FIG. 14), theinformation is indicative of the magnitude of the envelope power supplysignal EPS (FIG. 14). In this regard, in one embodiment of the RF PAcircuitry 30 (FIG. 14), the PA control circuitry 94 (FIG. 14) selectsthe one of the normal RF spectral emissions mode and the reduced RFspectral emissions mode based on the one of the group of RFcommunications bands, the indicated RF output power from the RF PAs, theindicated magnitude of the envelope power supply signal EPS (FIG. 14),or any combination thereof.

In one embodiment of the transceiver circuitry 34 (FIG. 6), thetransceiver circuitry 34 (FIG. 6) provides the information to the PAcontrol circuitry 94 (FIG. 14) via the digital communications bus 66(FIG. 14). In one embodiment of the transceiver circuitry 34 (FIG. 6),the transceiver circuitry 34 (FIG. 6) selects the one of the normal RFspectral emissions mode and the reduced RF spectral emissions mode andindicates the selection via the information. In one embodiment of the RFcommunications system 26 (FIG. 6), the RF communications system 26 (FIG.6) receives RF signals that are used by the transceiver circuitry 34(FIG. 6) to provide the information. The RF communications system 26(FIG. 6) may be part of a communications network and the received RFsignals may be indicative of network commands, network information, orthe like, which are used by the transceiver circuitry 34 (FIG. 6) toprovide the information.

Those skilled in the art will recognize improvements and modificationsto the preferred embodiments of the present disclosure. All suchimprovements and modifications are considered within the scope of theconcepts disclosed herein and the claims that follow.

What is claimed is:
 1. Circuitry comprising: radio frequency (RF) power amplifier (PA) circuitry comprising a quadrature RF PA and adapted to: receive and amplify an RF input signal using the quadrature RF PA to provide an RF output signal using an envelope power supply signal; operate in one of a normal RF spectral emissions mode and a reduced RF spectral emissions mode, wherein a quadrature balance of the quadrature RF PA is better in the reduced RF spectral emissions mode than in the normal RF spectral emissions mode; when reduced RF spectral emissions are required, operate in the reduced RF spectral emissions mode, such that the quadrature RF PA has higher PA linearity in the reduced RF spectral emissions mode than during the normal RF spectral emissions mode; and when reduced RF spectral emissions are not required, operate in the normal RF spectral emissions mode; and a PA envelope power supply adapted to provide the envelope power supply signal.
 2. The circuitry of claim 1 wherein when the reduced RF spectral emissions are not required, the RF PA circuitry is further adapted to operate in the normal RF spectral emissions mode.
 3. The circuitry of claim 1 wherein at a given RF output power, during the reduced RF spectral emissions mode, RF spectral emissions of the RF output signal are less than during the normal RF spectral emissions mode.
 4. The circuitry of claim 1 wherein: the RF output signal falls within one of a plurality of RF communications bands; the plurality of RF communications bands comprises a first RF communications band, which is about adjacent to a second RF communications band; and when the one of the plurality of RF communications bands is the first RF communications band, reduced RF spectral emissions are required.
 5. The circuitry of claim 1 wherein: the RF output signal falls within one of a plurality of RF communications bands; the plurality of RF communications bands comprises a first RF communications band, which is about adjacent to a second RF communications band; and when the one of the plurality of RF communications bands is the first RF communications band and an RF output power from the quadrature RF PA is higher than an RF output power threshold, reduced RF spectral emissions are required.
 6. The circuitry of claim 5 wherein the first RF communications band is a cellular communications band and the second RF communications band is a non-cellular communications band.
 7. The circuitry of claim 6 wherein the first RF communications band is a 3^(rd) Generation Partnership Project (3GPP) cellular communications band and the second RF communications band is a Public Safety Band.
 8. The circuitry of claim 7 wherein a frequency range of the first RF communications band is between about 777 megahertz and about 787 megahertz, and a frequency range of the second RF communications band is between about 788 megahertz and about 798 megahertz.
 9. The circuitry of claim 1 wherein at a given RF output power, during the reduced RF spectral emission mode, a magnitude of the envelope power supply signal is higher than during the normal RF spectral emissions mode.
 10. The circuitry of claim 1 wherein: the quadrature RF PA comprises a quadrature final stage; and during the reduced RF spectral emissions mode, a bias level of the quadrature final stage is different than during the normal RF spectral emissions mode to improve a quadrature balance of the quadrature final stage.
 11. The circuitry of claim 10 wherein: the quadrature RF PA comprises a quadrature driver stage; and during the reduced RF spectral emissions mode, a bias level of the quadrature driver stage is different than during the normal RF spectral emissions mode to improve a quadrature balance of the quadrature driver stage.
 12. The circuitry of claim 1 wherein: the quadrature RF PA comprises a quadrature driver stage; and during the reduced RF spectral emissions mode, a bias level of the quadrature driver stage is different than during the normal RF spectral emissions mode to improve a quadrature balance of the quadrature driver stage.
 13. The circuitry of claim 1 wherein the RF PA circuitry is hardwired to select the reduced RF spectral emissions mode.
 14. The circuitry of claim 1 wherein the RF PA circuitry comprises: the quadrature RF PA adapted to receive and amplify the RF input signal to provide the RF output signal using the envelope power supply signal; PA control circuitry adapted to select the one of the normal RF spectral emissions mode and the reduced RF spectral emissions mode; and PA bias circuitry coupled between the PA control circuitry and the quadrature RF PA.
 15. The circuitry of claim 14 wherein: the RF PA circuitry further comprises a PA-digital communications interface (PA-DCI) coupled between a digital communications bus and the PA control circuitry; and the PA control circuitry is further adapted to receive information via the digital communications bus and select the one of the normal RF spectral emissions mode and the reduced RF spectral emissions mode based on the information.
 16. The circuitry of claim 15 wherein: the RF output signal falls within one of a plurality of RF communications bands; and the information identifies the one of the plurality of RF communications bands.
 17. The circuitry of claim 16 wherein the information is indicative of an RF output power from the quadrature RF PA.
 18. The circuitry of claim 16 wherein the information is indicative of a magnitude of the envelope power supply signal.
 19. A method comprising: receiving and amplifying a radio frequency (RF) input signal using a quadrature RF power amplifier (PA) to provide an RF output signal using an envelope power supply signal; operating in one of a normal RF spectral emissions mode and a reduced RF spectral emissions mode; when reduced RF spectral emissions are required, operating in the reduced RF spectral emissions mode, wherein a quadrature balance of the quadrature RF PA is better in the reduced spectral emissions mode than in the normal RF spectral emissions mode; when reduced RF spectral emissions are not required, operating in the normal RF spectral emissions mode; and providing the envelope power supply signal. 